Rank and resource set signaling techniques for multiple transmission-reception point communications

ABSTRACT

Methods, systems, and devices for wireless communication are described in which a user equipment (UE) may transmit one or more uplink communications to multiple transmission-reception points (TRPs). Transmission parameters for each repetition may be based on parameters (e.g., a number of antenna ports, a spatial domain filter or beam, a rank or number of layers, or any combinations thereof) that are determined from an indication of whether the repetitions are to use different sounding reference signal (SRS) resource sets, and indicated SRS resource of each SRS resource set. The indication may include a same number of bits regardless of whether one SRS resource set is used or multiple SRS resource sets are used, and may be based on a prior configuration of the UE.

CROSS REFERENCE

The present Application for Patent claims the benefit of U.S.Provisional Patent Application No. 63/131,289 by KHOSHNEVISAN et al.,entitled “RANK AND RESOURCE SET SIGNALING TECHNIQUES FOR MULTIPLETRANSMISSION-RECEPTION POINT COMMUNICATIONS,” filed Dec. 28, 2020,assigned to the assignee hereof, and expressly incorporated by referenceherein.

FIELD OF TECHNOLOGY

The following relates to wireless communication, including rank andresource set signaling techniques for multiple transmission-receptionpoint (TRP) communications.

BACKGROUND

Wireless communications systems are widely deployed to provide varioustypes of communication content such as voice, video, packet data,messaging, broadcast, and so on. These systems may be capable ofsupporting communication with multiple users by sharing the availablesystem resources (e.g., time, frequency, and power). Examples of suchmultiple-access systems include fourth generation (4G) systems such asLong Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, orLTE-A Pro systems, and fifth generation (5G) systems which may bereferred to as New Radio (NR) systems. These systems may employtechnologies such as code division multiple access (CDMA), time divisionmultiple access (TDMA), frequency division multiple access (FDMA),orthogonal frequency division multiple access (OFDMA), or discreteFourier transform spread orthogonal frequency division multiplexing(DFT-S-OFDM). A wireless multiple-access communications system mayinclude one or more base stations or one or more network access nodes,each simultaneously supporting communication for multiple communicationdevices, which may be otherwise known as user equipment (UE).

Some wireless communications systems may support communications usingone or multiple antenna arrays at different devices. For instance, anetwork may communicate with a UE using one or moretransmission/reception point (TRPs), where each TRP and the UE may haveone or more antenna arrays to form directional beams. Efficientcommunications between UEs and one or multiple TRPs may help to enhancenetwork throughput, latency, and reliability, and thus techniques tofurther improve efficient communications are desirable.

SUMMARY

The described techniques relate to improved methods, systems, devices,and apparatuses that support rank and resource set signaling techniquesfor multiple transmission-reception point (TRP) communications. Variousaspects provide techniques for communications between a user equipment(UE) and multiple TRPs in which the UE may transmit an uplinkcommunication to one or multiple TRPs to enhance the likelihood ofsuccessful receipt of the uplink communication. In some cases, the UEmay transmit uplink communications based on parameters (e.g., a numberof antenna ports, a spatial domain filter or beam, a rank or number oflayers, or any combinations thereof) that are determined from one ormore sounding reference signal (SRS) resources. The SRS resources may beselected from one or two sets of SRS resources that are configured atthe UE, and may be indicated in control information provided to the UE.

In some cases, a base station or TRP may transmit configurationinformation to a UE that indicates a number of bits that are to beincluded in a control information field that indicates one or two SRSresource sets with which a first uplink communication is to beassociated. Based on the configuration information, the UE may receivethe control information, and determine whether one or two SRS resourcesets are associated with the first uplink communication, and transmitthe first uplink communication based on the one or two SRS resourcesets. In some cases, the number of bits in the control information aredetermined based on a maximum number of bits needed for indicating SRSresources from one SRS resource set or for indicating SRS resources fromtwo SRS resource sets. In other cases, available combinations of SRSresources from one or two SRS resource sets may be jointly coded andtransmitted in a same resource indicator field having a number of bitsthat is based on the number of available combinations of SRS resources.

A method for wireless communication at a UE is described. The method mayinclude receiving, from a base station, a control informationconfiguration that indicates a quantity of bits that are to be includedin a control information field that indicates one or two resource setswith which a first uplink communication is to be associated, receiving,from the base station, a first control information communication thatincludes the control information field and that schedules the firstuplink communication for the UE, determining, based on the first controlinformation communication and the control information configuration,whether one or two SRS resource sets are associated with the firstuplink communication, and transmitting the first uplink communication tothe base station based on the determining.

An apparatus for wireless communication at a UE is described. Theapparatus may include a processor, memory in electronic communicationwith the processor, and instructions stored in the memory. Theinstructions may be executable by the processor to cause the apparatusto receive, from a base station, a control information configurationthat indicates a quantity of bits that are to be included in a controlinformation field that indicates one or two SRS resource sets with whicha first uplink communication is to be associated, receive, from the basestation, a first control information communication that includes thecontrol information field and that schedules the first uplinkcommunication for the UE, determine, based on the first controlinformation communication and the control information configuration,whether one or two SRS resource sets are associated with the firstuplink communication, and transmit the first uplink communication to thebase station based on the determining.

Another apparatus for wireless communication at a UE is described. Theapparatus may include means for receiving, from a base station, acontrol information configuration that indicates a quantity of bits thatare to be included in a control information field that indicates one ortwo SRS resource sets with which a first uplink communication is to beassociated, means for receiving, from the base station, a first controlinformation communication that includes the control information fieldand that schedules the first uplink communication for the UE, means fordetermining, based on the first control information communication andthe control information configuration, whether one or two SRS resourcesets are associated with the first uplink communication, and means fortransmitting the first uplink communication to the base station based onthe determining.

A non-transitory computer-readable medium storing code for wirelesscommunication at a UE is described. The code may include instructionsexecutable by a processor to receive, from a base station, a controlinformation configuration that indicates a quantity of bits that are tobe included in a control information field that indicates one or two SRSresource sets with which a first uplink communication is to beassociated, receive, from the base station, a first control informationcommunication that includes the control information field and thatschedules the first uplink communication for the UE, determine, based onthe first control information communication and the control informationconfiguration, whether one or two SRS resource sets are associated withthe first uplink communication, and transmit the first uplinkcommunication to the base station based on the determining.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the determining may includeoperations, features, means, or instructions for determining, based onthe first control information communication and the control informationconfiguration, the number of SRS resources for each SRS resource setassociated with the first uplink communication. In some examples of themethod, apparatuses, and non-transitory computer-readable mediumdescribed herein, the determining may include operations, features,means, or instructions for determining, based on a first bit of thefirst control information communication, whether one or two SRS resourcesets are associated with the first uplink communication, and where thecontrol information field includes a set of bits that indicate a numberof SRS resources for each SRS resource set associated with the firstuplink communication. In some examples of the method, apparatuses, andnon-transitory computer-readable medium described herein, the first bitmay be an initial bit of the control information field, or may be in aseparate field in the first control information communication.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the set of bits includes amaximum of a first number of bits or a second number of bits, the firstnumber of bits determined based on a first maximum rank when one SRSresource set is associated with the first uplink communication, and thesecond number of bits determined based on a second maximum rank when twoSRS resource sets are associated with the first uplink communication. Insome examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the second maximum rank isless than the first maximum rank. In some examples of the method,apparatuses, and non-transitory computer-readable medium describedherein, the second maximum rank is a fixed value or a configured valuethat is provided with the control information configuration. In someexamples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the configured value of thesecond maximum rank may be based on a capability of the UE that istransmitted to the base station. In some examples of the method,apparatuses, and non-transitory computer-readable medium describedherein, zero-padding may be used in the set of bits when a number ofbits necessary to indicate the rank of one or both of the SRS resourcesets is less than a total number of bits of the set of bits.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the first number of bits isdetermined based on the first SRS resource set having a different numberof SRS resources than the second SRS resource set. In some examples ofthe method, apparatuses, and non-transitory computer-readable mediumdescribed herein, the first number of bits may be associated with thefirst SRS resource set. In some examples of the method, apparatuses, andnon-transitory computer-readable medium described herein, the firstnumber of bits may be associated with either the first SRS resource setor the second SRS resource set, and a separate bit in the controlinformation field provides an indication of which of the first SRSresource set or the second SRS resource set is associated with the firstuplink communication.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the second number of bits maybe associated with both the first SRS resource set and the second SRSresource set, and a first subset of the second number of bits indicatesone or more SRS resources within the first SRS resource set and a secondsubset of the second number of bits indicates one or more SRS resourceswithin the second SRS resource set. In some examples of the method,apparatuses, and non-transitory computer-readable medium describedherein, the second number of bits may be associated with both the firstSRS resource set and the second SRS resource set, and provides a jointindication of one or more SRS resources within each of the SRS resourcesets based on a same number of layers associated with each SRS resourceset.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the determining may includeoperations, features, means, or instructions for decoding the controlinformation field to identify a set of bits and identifying, based on amapping for the set of bits, a number of SRS resources for each SRSresource set associated with the first uplink communication.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, a first SRS resource set maybe ordered ahead of a second SRS resource set, and the quantity of bitsthat are included in the control information field is determined as asum of a first number of possibilities to indicate a first number of SRSresources associated with the first SRS resource set when a single SRSresource set is associated with the first uplink communication, and asecond number of possibilities to indicate a second number of SRSresources associated with both the first and the second SRS resource setwhen both the first SRS resource set and the second SRS resource set areassociated with the first uplink communication.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, a first SRS resource set or asecond SRS resource set may be ordered as an initial SRS resource setand the quantity of bits that is included in the control informationfield is determined as a sum of a first number of possibilities toindicate a first number of SRS resources associated with the initial SRSresource set when a single SRS resource set is associated with the firstuplink communication, and a second number of possibilities to indicate asecond number of SRS resources associated with both the first and thesecond SRS resource set when a both the first SRS resource set and thesecond SRS resource set are associated with the first uplinkcommunication. In some examples of the method, apparatuses, andnon-transitory computer-readable medium described herein, different bitvalues of the control information field are mapped to differentpossibilities of a number of the SRS resources that are associated withthe first uplink communication.

A method for wireless communication at a base station is described. Themethod may include transmitting, to a UE, a control informationconfiguration that indicates a quantity of bits that are to be includedin a control information field that indicates one or two SRS resourcesets with which a first uplink communication is to be associated,determining whether one SRS resource set or two SRS resource sets areassociated with the first uplink communication, transmitting, to the UE,a first control information communication that includes the controlinformation field and that schedules the first uplink communication forthe UE and indicates whether one SRS resource set or two SRS resourcesets are associated with the first uplink communication, and receivingthe first uplink communication from the UE based on the first controlinformation communication.

An apparatus for wireless communication at a base station is described.The apparatus may include a processor, memory in electroniccommunication with the processor, and instructions stored in the memory.The instructions may be executable by the processor to cause theapparatus to transmit, to a UE, a control information configuration thatindicates a quantity of bits that are to be included in a controlinformation field that indicates one or two SRS resource sets with whicha first uplink communication is to be associated, determine whether oneSRS resource set or two SRS resource sets are associated with the firstuplink communication, transmit, to the UE, a first control informationcommunication that includes the control information field and thatschedules the first uplink communication for the UE and indicateswhether one SRS resource set or two SRS resource sets are associatedwith the first uplink communication, and receive the first uplinkcommunication from the UE based on the first control informationcommunication.

Another apparatus for wireless communication at a base station isdescribed. The apparatus may include means for transmitting, to a UE, acontrol information configuration that indicates a quantity of bits thatare to be included in a control information field that indicates one ortwo SRS resource sets with which a first uplink communication is to beassociated, means for determining whether one SRS resource set or twoSRS resource sets are associated with the first uplink communication,means for transmitting, to the UE, a first control informationcommunication that includes the control information field and thatschedules the first uplink communication for the UE and indicateswhether one SRS resource set or two SRS resource sets are associatedwith the first uplink communication, and means for receiving the firstuplink communication from the UE based on the first control informationcommunication.

A non-transitory computer-readable medium storing code for wirelesscommunication at a base station is described. The code may includeinstructions executable by a processor to transmit, to a UE, a controlinformation configuration that indicates a quantity of bits that are tobe included in a control information field that indicates one or two SRSresource sets with which a first uplink communication is to beassociated, determine whether one SRS resource set or two SRS resourcesets are associated with the first uplink communication, transmit, tothe UE, a first control information communication that includes thecontrol information field and that schedules the first uplinkcommunication for the UE and indicates whether one SRS resource set ortwo SRS resource sets are associated with the first uplinkcommunication, and receive the first uplink communication from the UEbased on the first control information communication.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the control information fieldfurther indicates a number of SRS resources to be associated with thefirst uplink communication. In some examples of the method, apparatuses,and non-transitory computer-readable medium described herein, a firstbit of the first control information communication indicates whether oneor two SRS resource sets are associated with the first uplinkcommunication, and where the control information field includes a set ofbits that indicate a number of SRS resources for each SRS resource setassociated with the first uplink communication. In some examples of themethod, apparatuses, and non-transitory computer-readable mediumdescribed herein, the first bit may be an initial bit of the controlinformation field, or may be in a separate field in the first controlinformation communication.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the set of bits includes amaximum of a first number of bits or a second number of bits, the firstnumber of bits determined based on a first maximum rank when one SRSresource set is associated with the first uplink communication, and thesecond number of bits determined based on a second maximum rank set whentwo SRS resource sets are associated with the first uplinkcommunication. In some examples of the method, apparatuses, andnon-transitory computer-readable medium described herein, the secondmaximum rank is less than the first maximum rank. In some examples ofthe method, apparatuses, and non-transitory computer-readable mediumdescribed herein, the second maximum rank may be a fixed value or aconfigured value that is provided with the control informationconfiguration. In some examples of the method, apparatuses, andnon-transitory computer-readable medium described herein, the configuredvalue of the second maximum rank may be based on a capability of the UEthat is transmitted to the base station. In some examples of the method,apparatuses, and non-transitory computer-readable medium describedherein, zero-padding may be used in the set of bits when a number ofbits necessary to indicate the rank of one or both of the SRS resourcesets is less than a total number of bits of the set of bits.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the first number of bits maybe determined based on the first SRS resource set having a differentnumber of SRS resources than the second SRS resource set. In someexamples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the first number of bits maybe associated with the first SRS resource set. In some examples of themethod, apparatuses, and non-transitory computer-readable mediumdescribed herein, the first number of bits may be associated with eitherthe first SRS resource set or the second SRS resource set, and aseparate bit in the control information field provides an indication ofwhich of the first SRS resource set or the second SRS resource set isassociated with the first uplink communication.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the second number of bits maybe associated with both the first SRS resource set and the second SRSresource set, and a first subset of the second number of bits indicatesone or more SRS resources within the first SRS resource set and a secondsubset of the second number of bits indicates one or more SRS resourceswithin the second SRS resource set. In some examples of the method,apparatuses, and non-transitory computer-readable medium describedherein, the second number of bits may be associated with both the firstSRS resource set and the second SRS resource set, and provides a jointindication of one or more SRS resources within each of the SRS resourcesets based on a same number of layers associated with each SRS resourceset.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for determining a number ofSRS resources for each SRS resource set associated with the first uplinkcommunication, identifying a mapping between a codepoint and thedetermined number of SRS resources, and where the control informationfield indicates the codepoint. In some examples of the method,apparatuses, and non-transitory computer-readable medium describedherein, different bit values of the control information field may bemapped to different possibilities of the SRS resources that areassociated with the first uplink communication.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, a first SRS resource set maybe ordered ahead of a second SRS resource set, and the quantity of bitsthat are included in the control information field is determined as asum of a first number of possibilities to indicate a first number of SRSresources associated with the first SRS resource set when a single SRSresource set is associated with the first uplink communication, and asecond number of possibilities to indicate a second number of SRSresources associated with both the first and the second SRS resource setwhen both the first SRS resource set and the second SRS resource set areassociated with the first uplink communication.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, a first SRS resource set or asecond SRS resource set may be ordered as an initial SRS resource setand the quantity of bits that are included in the control informationfield is determined as a sum of a first number of possibilities toindicate a first number of SRS resources associated with the initial SRSresource set when a single SRS resource set is associated with the firstuplink communication, and a second number of possibilities to indicate asecond number of SRS resources associated with both the first and thesecond SRS resource set when a both the first SRS resource set and thesecond SRS resource set are associated with the first uplinkcommunication.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a wireless communications system thatsupports rank and resource set signaling techniques for multipletransmission-reception point (TRP) communications in accordance withaspects of the present disclosure.

FIG. 2 illustrates an example of a portion of a wireless communicationssystem that supports rank and resource set signaling techniques formultiple TRP communications in accordance with aspects of the presentdisclosure.

FIG. 3 illustrates an example of control and shared channelcommunications that support rank and resource set signaling techniquesfor multiple TRP communications in accordance with aspects of thepresent disclosure.

FIG. 4 illustrates an example of control information that supports rankand resource set signaling techniques for multiple TRP communications inaccordance with aspects of the present disclosure.

FIG. 5 illustrates an example of a process flow that supports rank andresource set signaling techniques for multiple TRP communications inaccordance with aspects of the present disclosure.

FIGS. 6 and 7 show block diagrams of devices that support rank andresource set signaling techniques for multiple TRP communications inaccordance with aspects of the present disclosure.

FIG. 8 shows a block diagram of a communications manager that supportsrank and resource set signaling techniques for multiple TRPcommunications in accordance with aspects of the present disclosure.

FIG. 9 shows a diagram of a system including a device that supports rankand resource set signaling techniques for multiple TRP communications inaccordance with aspects of the present disclosure.

FIGS. 10 and 11 show block diagrams of devices that support rank andresource set signaling techniques for multiple TRP communications inaccordance with aspects of the present disclosure.

FIG. 12 shows a block diagram of a communications manager that supportsrank and resource set signaling techniques for multiple TRPcommunications in accordance with aspects of the present disclosure.

FIG. 13 shows a diagram of a system including a device that supportsrank and resource set signaling techniques for multiple TRPcommunications in accordance with aspects of the present disclosure.

FIGS. 14 through 19 show flowcharts illustrating methods that supportrank and resource set signaling techniques for multiple TRPcommunications in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

In some wireless communications systems, the network may communicatewith a user equipment (UE) using one or more transmission-receptionpoints (TRPs). For example, the network may communicate with the UEusing a single TRP at a base station, using multiple TRPs at a same basestation, or using multiple TRPs across multiple base stations. In suchsystems, transmission parameters of each device (e.g., each UE, eachTRP, each base station) may vary across the system (e.g., becausedifferent operating frequencies, different beams, different numbers ofantenna ports, etc.), and thus separate parameters may be indicated forcommunications with different TRPs. For example, in a multi-TRP system,two or more TRPs may coordinate and configure a UE to transmit multiplesets of repetitions of an uplink communication in which one set ofrepetitions are directed to a first TRP and a different set ofrepetitions are directed to a second TRP. Such techniques may enhancethe likelihood of at least one of the TRPs successfully receiving theuplink communication, and thus enhance communications reliability.However, when uplink transmissions to different TRPs have differenttransmission parameters, flexibility in providing an indication of thedifferent transmission parameters may be desired in order to providesufficient information to the UE for transmissions to different TRPs.Existing configuration and control information techniques may notprovide sufficient information for communications to multiple TRPs foran uplink communication in some cases. Various aspects of the presentdisclosure provide enhanced techniques that allow for flexible andefficient signaling of configuration and control information associatedwith multiple TRPs.

In some cases, the UE may transmit uplink communications based onparameters (e.g., a number of antenna ports, a spatial domain filter orbeam, a rank or number of layers, or any combinations thereof) that aredetermined from a sounding reference signal (SRS) resource. The SRSresource may be selected from a set of SRS resources that are configuredat the UE, and may be indicated in control information provided to theUE. In some cases, multiple sets of SRS resources may be configured atthe UE, and one or multiple indicators in the control information (e.g.,downlink control information (DCI)) may be mapped to SRS resources ofone or more of the sets of SRS resources.

In some deployments, SRS resources may be used to indicate uplink sharedchannel (e.g., physical uplink shared channel (PUSCH)) transmissionparameters as well as SRS transmission parameters. In some cases, twotypes of PUSCH transmissions are supported, namely codebook andnon-codebook PUSCH transmissions. For non-codebook based uplinktransmissions, a UE may be configured with one SRS resource set with“usage” set to “noncodebook.” In such cases, a maximum of four SRSresources within the one SRS resource set can be configured for the UE,and each SRS resource has one associated antenna port. A SRS resourceindicator (SRI) field in a DCI transmission (e.g., a DCI that schedulesPUSCH) indicates one or multiple SRS resources, and the number ofindicated SRS resources determines the rank (e.g., number of layers) forthe scheduled PUSCH. The PUSCH communication is transmitted with a sameprecoder as well as spatial domain filter (e.g., beam) as the indicatedSRS resources. The SRI may include a bit field that is mapped to anindex of configured SRS resources in the SRS resource set, where a sizeof the bit field is based on a number of configured SRS resources in theSRS resource set and the number of layers of the PUSCH transmission.

In cases where multiple instances of an uplink communication (e.g., asame transport block (TB)) are transmitted to multiple TRPs, it may beuseful to configure multiple SRS resource sets to may provide additionaloptions for indicating uplink transmission parameters for the multipleuplink communications. For example, if a first link between a UE and afirst TRP is blocked, a first repetition of an uplink transmission tothe first TRP may not be successfully received. However, if a secondlink between the UE and a second TRP is not blocked, a second repetitionof the uplink transmission to the second TRP may be successfullyreceived and decoded. Thus, such techniques may increase diversity incommunications and thereby enhance reliability and efficiency in caseswhere one or more links may experience relatively poor channelconditions. However, in existing deployments all of the repetitions aretransmitted with the same beam (e.g., the SRI field of the DCI isapplied to all the repetitions), and when different PUSCH repetitionsare intended to be received at different TRPs/panels/antennas at thebase station side, such a same beam for all the repetitions may not bewell suited for receipt at each of the different TRPs/panels/antennas.In accordance with techniques as discussed herein, a base station or TRPmay configure multiple SRS resource sets that may be used for differentrepetitions of different TRPs/panels/antennas. In some cases, differentPUSCH transmission occasions (i.e. repetitions) corresponding to thesame TB are transmitted in different slots or mini-slots, and a numberof repetitions may be configured (e.g., via radio resource control (RRC)signaling) or may be indicated dynamically (e.g., in DCI that schedulesthe uplink communication, such as in a time domain resource assignment(TDRA) field).

In cases where multiple SRS resource sets are configured (e.g., two SRSresource sets that are configured for two TRPs), simply transmitting twoseparate SRI fields in the DCI may result in an increased DCI overhead,as twice as many bits are needed to provide the separate SRI fields. Inaccordance with some aspects of the present disclosure, resourceindications for multiple different sets of SRS resources may be providedwith reduced overhead relative to simply transmitting two SRI fields.Further, resource indications may be provided that have a same number ofbits in DCI, such that different SRS resources from one or more SRSresource sets may be indicated in an information field having aconsistent size, which may provide for more efficient processing at a UE(e.g., the UE does not have to blind decode multiple candidate DCI sizesor formats).

Such techniques provide that SRS resources for an uplink communicationmay be indicated for different modes, including a first mode in which asingle SRS resource set is used for an uplink communication (e.g., asingle beam PUSCH and/or transmissions to a single TRP), and a secondmode in which two SRS resource sets are used for an uplink communication(e.g., for a PUSCH with two sets of repetitions transmitted with tworespective beams and/or to multiple TRPs). In cases of the first mode, amaximum number of layers that can be indicated may be denoted asL_(max). Hence, a resource indication (e.g., SRI) can indicate up toLmax SRS resources within one SRS resource set. In cases of the secondmode, a maximum number of layers that can be indicated for each SRSresource set may be denoted as L′_(max), which is smaller than L_(max)for an associated SRS resource set. Thus, there are fewer possibilitiesfor indication of one or more SRS resources when the second mode isused, and two indications are needed (i.e., one associated with thefirst SRS resource set and another associated with the second SRSresource set). The reason that L′_(max) is less than L_(max) is thatwhen a base station elects to allocate an uplink transmission usingmultiple repetitions on different beams (e.g., due to relatively poorchannel conditions, reliability targets for the communication, latencytargets for the communication, etc.), the base station may schedule thetransmission with a smaller number of layers in order to provideenhanced reliability. Thus, the number of bits that are needed in theDCI for SRI field(s) may be determined, in accordance with varioustechniques as discussed herein, based on a maximum number of bits neededfor the first mode and the second mode. In other cases, information forwhich mode is to be used as well as associated resource indications fromthe one or more sets of SRS resources, may be jointly coded andindicated by the same field (e.g., a same set of bits) of the DCI (e.g.,a mapping is provided for the mode and SRS resources within the sets ofSRS resources).

In some cases, a base station or TRP may transmit configurationinformation to a UE that indicates a number of bits that are to beincluded in a control information field that indicates one or two SRSresource sets with which a first uplink communication is to beassociated. Based on the configuration information, the UE may receivethe control information, and determine whether one or two SRS resourcesets are associated with the first uplink communication, and transmitthe first uplink communication based on the one or two SRS resource setsand indicated SRS resources within the one or two SRS resource sets. Insome cases, the number of bits in the control information are determinedbased on a maximum number of bits needed for indicating SRS resourcesfrom one SRS resource set or for indicating SRS resources from two SRSresource sets. In other cases, available combinations of SRS resourcesfrom one or two SRS resource sets may be jointly coded and transmittedin a same resource indicator field having a number of bits that is basedon the number of available combinations of SRS resources.

Aspects of the disclosure are initially described in the context ofwireless communications systems. Aspects of the disclosure are furtherillustrated by and described with reference to SRS resources formultiple repetitions, process flow diagrams, apparatus diagrams, systemdiagrams, and flowcharts that relate to rank and resource set signalingtechniques for multiple TRP communications.

FIG. 1 illustrates an example of a wireless communications system 100that supports rank and resource set signaling techniques for multipleTRP communications in accordance with aspects of the present disclosure.The wireless communications system 100 may include one or more basestations 105, one or more UEs 115, and a core network 130. In someexamples, the wireless communications system 100 may be a Long TermEvolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pronetwork, or a New Radio (NR) network. In some examples, the wirelesscommunications system 100 may support enhanced broadband communications,ultra-reliable (e.g., mission critical) communications, low latencycommunications, communications with low-cost and low-complexity devices,or any combination thereof.

The base stations 105 may be dispersed throughout a geographic area toform the wireless communications system 100 and may be devices indifferent forms or having different capabilities. The base stations 105and the UEs 115 may wirelessly communicate via one or more communicationlinks 125. Each base station 105 may provide a coverage area 110 overwhich the UEs 115 and the base station 105 may establish one or morecommunication links 125. The coverage area 110 may be an example of ageographic area over which a base station 105 and a UE 115 may supportthe communication of signals according to one or more radio accesstechnologies.

The UEs 115 may be dispersed throughout a coverage area 110 of thewireless communications system 100, and each UE 115 may be stationary,or mobile, or both at different times. The UEs 115 may be devices indifferent forms or having different capabilities. Some example UEs 115are illustrated in FIG. 1. The UEs 115 described herein may be able tocommunicate with various types of devices, such as other UEs 115, thebase stations 105, or network equipment (e.g., core network nodes, relaydevices, integrated access and backhaul (IAB) nodes, or other networkequipment), as shown in FIG. 1.

The base stations 105 may communicate with the core network 130, or withone another, or both. For example, the base stations 105 may interfacewith the core network 130 through one or more backhaul links 120 (e.g.,via an S1, N2, N3, or other interface). The base stations 105 maycommunicate with one another over the backhaul links 120 (e.g., via anX2, Xn, or other interface) either directly (e.g., directly between basestations 105), or indirectly (e.g., via core network 130), or both. Insome examples, the backhaul links 120 may be or include one or morewireless links.

One or more of the base stations 105 described herein may include or maybe referred to by a person having ordinary skill in the art as a basetransceiver station, a radio base station, an access point, a radiotransceiver, a NodeB, an eNodeB (eNB), a next-generation NodeB or agiga-NodeB (either of which may be referred to as a gNB), a Home NodeB,a Home eNodeB, or other suitable terminology.

A UE 115 may include or may be referred to as a mobile device, awireless device, a remote device, a handheld device, or a subscriberdevice, or some other suitable terminology, where the “device” may alsobe referred to as a unit, a station, a terminal, or a client, amongother examples. A UE 115 may also include or may be referred to as apersonal electronic device such as a cellular phone, a personal digitalassistant (PDA), a tablet computer, a laptop computer, or a personalcomputer. In some examples, a UE 115 may include or be referred to as awireless local loop (WLL) station, an Internet of Things (IoT) device,an Internet of Everything (IoE) device, or a machine type communications(MTC) device, among other examples, which may be implemented in variousobjects such as appliances, or vehicles, meters, among other examples.

The UEs 115 described herein may be able to communicate with varioustypes of devices, such as other UEs 115 that may sometimes act as relaysas well as the base stations 105 and the network equipment includingmacro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations,among other examples, as shown in FIG. 1.

The UEs 115 and the base stations 105 may wirelessly communicate withone another via one or more communication links 125 over one or morecarriers. The term “carrier” may refer to a set of radio frequencyspectrum resources having a defined physical layer structure forsupporting the communication links 125. For example, a carrier used fora communication link 125 may include a portion of a radio frequencyspectrum band (e.g., a bandwidth part (BWP)) that is operated accordingto one or more physical layer channels for a given radio accesstechnology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layerchannel may carry acquisition signaling (e.g., synchronization signals,system information), control signaling that coordinates operation forthe carrier, user data, or other signaling. The wireless communicationssystem 100 may support communication with a UE 115 using carrieraggregation or multi-carrier operation. A UE 115 may be configured withmultiple downlink component carriers and one or more uplink componentcarriers according to a carrier aggregation configuration. Carrieraggregation may be used with both frequency division duplexing (FDD) andtime division duplexing (TDD) component carriers.

In some examples (e.g., in a carrier aggregation configuration), acarrier may also have acquisition signaling or control signaling thatcoordinates operations for other carriers. A carrier may be associatedwith a frequency channel (e.g., an evolved universal mobiletelecommunication system terrestrial radio access (E-UTRA) absoluteradio frequency channel number (EARFCN)) and may be positioned accordingto a channel raster for discovery by the UEs 115. A carrier may beoperated in a standalone mode where initial acquisition and connectionmay be conducted by the UEs 115 via the carrier, or the carrier may beoperated in a non-standalone mode where a connection is anchored using adifferent carrier (e.g., of the same or a different radio accesstechnology).

The communication links 125 shown in the wireless communications system100 may include uplink transmissions from a UE 115 to a base station105, or downlink transmissions from a base station 105 to a UE 115.Carriers may carry downlink or uplink communications (e.g., in an FDDmode) or may be configured to carry downlink and uplink communications(e.g., in a TDD mode).

A carrier may be associated with a particular bandwidth of the radiofrequency spectrum, and in some examples the carrier bandwidth may bereferred to as a “system bandwidth” of the carrier or the wirelesscommunications system 100. For example, the carrier bandwidth may be oneof a number of determined bandwidths for carriers of a particular radioaccess technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 megahertz(MHz)). Devices of the wireless communications system 100 (e.g., thebase stations 105, the UEs 115, or both) may have hardwareconfigurations that support communications over a particular carrierbandwidth or may be configurable to support communications over one of aset of carrier bandwidths. In some examples, the wireless communicationssystem 100 may include base stations 105 or UEs 115 that supportsimultaneous communications via carriers associated with multiplecarrier bandwidths. In some examples, each served UE 115 may beconfigured for operating over portions (e.g., a sub-band, a BWP) or allof a carrier bandwidth.

Signal waveforms transmitted over a carrier may be made up of multiplesubcarriers (e.g., using multi-carrier modulation (MCM) techniques suchas orthogonal frequency division multiplexing (OFDM) or discrete Fouriertransform spread OFDM (DFT-S-OFDM)). In a system employing MCMtechniques, a resource element may consist of one symbol period (e.g., aduration of one modulation symbol) and one subcarrier, where the symbolperiod and subcarrier spacing are inversely related. The number of bitscarried by each resource element may depend on the modulation scheme(e.g., the order of the modulation scheme, the coding rate of themodulation scheme, or both). Thus, the more resource elements that a UE115 receives and the higher the order of the modulation scheme, thehigher the data rate may be for the UE 115. A wireless communicationsresource may refer to a combination of a radio frequency spectrumresource, a time resource, and a spatial resource (e.g., spatial layersor beams), and the use of multiple spatial layers may further increasethe data rate or data integrity for communications with a UE 115.

One or more numerologies for a carrier may be supported, where anumerology may include a subcarrier spacing (Δf) and a cyclic prefix. Acarrier may be divided into one or more BWPs having the same ordifferent numerologies. In some examples, a UE 115 may be configuredwith multiple BWPs. In some examples, a single BWP for a carrier may beactive at a given time and communications for the UE 115 may berestricted to one or more active BWPs.

The time intervals for the base stations 105 or the UEs 115 may beexpressed in multiples of a basic time unit which may, for example,refer to a sampling period of T_(s)=1/(Δf_(max)·N_(f)) seconds, whereΔf_(max) may represent the maximum supported subcarrier spacing, andN_(f) may represent the maximum supported discrete Fourier transform(DFT) size. Time intervals of a communications resource may be organizedaccording to radio frames each having a specified duration (e.g., 10milliseconds (ms)). Each radio frame may be identified by a system framenumber (SFN) (e.g., ranging from 0 to 1023).

Each frame may include multiple consecutively numbered subframes orslots, and each subframe or slot may have the same duration. In someexamples, a frame may be divided (e.g., in the time domain) intosubframes, and each subframe may be further divided into a number ofslots. Alternatively, each frame may include a variable number of slots,and the number of slots may depend on subcarrier spacing. Each slot mayinclude a number of symbol periods (e.g., depending on the length of thecyclic prefix prepended to each symbol period). In some wirelesscommunications systems 100, a slot may further be divided into multiplemini-slots containing one or more symbols. Excluding the cyclic prefix,each symbol period may contain one or more (e.g., N_(f)) samplingperiods. The duration of a symbol period may depend on the subcarrierspacing or frequency band of operation.

A subframe, a slot, a mini-slot, or a symbol may be the smallestscheduling unit (e.g., in the time domain) of the wirelesscommunications system 100 and may be referred to as a transmission timeinterval (TTI). In some examples, the TTI duration (e.g., the number ofsymbol periods in a TTI) may be variable. Additionally or alternatively,the smallest scheduling unit of the wireless communications system 100may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs)).

Physical channels may be multiplexed on a carrier according to varioustechniques. A physical control channel and a physical data channel maybe multiplexed on a downlink carrier, for example, using one or more oftime division multiplexing (TDM) techniques, frequency divisionmultiplexing (FDM) techniques, or hybrid TDM-FDM techniques. A controlregion (e.g., a control resource set (CORESET)) for a physical controlchannel may be defined by a number of symbol periods and may extendacross the system bandwidth or a subset of the system bandwidth of thecarrier. One or more control regions (e.g., CORESETs) may be configuredfor a set of the UEs 115. For example, one or more of the UEs 115 maymonitor or search control regions for control information according toone or more search space sets, and each search space set may include oneor multiple control channel candidates in one or more aggregation levelsarranged in a cascaded manner. An aggregation level for a controlchannel candidate may refer to a number of control channel resources(e.g., control channel elements (CCEs)) associated with encodedinformation for a control information format having a given payloadsize. Search space sets may include common search space sets configuredfor sending control information to multiple UEs 115 and UE-specificsearch space sets for sending control information to a specific UE 115.

Each base station 105 may provide communication coverage via one or morecells, for example a macro cell, a small cell, a hot spot, or othertypes of cells, or any combination thereof. The term “cell” may refer toa logical communication entity used for communication with a basestation 105 (e.g., over a carrier) and may be associated with anidentifier for distinguishing neighboring cells (e.g., a physical cellidentifier (PCID), a virtual cell identifier (VCID), or others). In someexamples, a cell may also refer to a geographic coverage area 110 or aportion of a geographic coverage area 110 (e.g., a sector) over whichthe logical communication entity operates. Such cells may range fromsmaller areas (e.g., a structure, a subset of structure) to larger areasdepending on various factors such as the capabilities of the basestation 105. For example, a cell may be or include a building, a subsetof a building, or exterior spaces between or overlapping with geographiccoverage areas 110, among other examples.

A macro cell generally covers a relatively large geographic area (e.g.,several kilometers in radius) and may allow unrestricted access by theUEs 115 with service subscriptions with the network provider supportingthe macro cell. A small cell may be associated with a lower-powered basestation 105, as compared with a macro cell, and a small cell may operatein the same or different (e.g., licensed, unlicensed) frequency bands asmacro cells. Small cells may provide unrestricted access to the UEs 115with service subscriptions with the network provider or may providerestricted access to the UEs 115 having an association with the smallcell (e.g., the UEs 115 in a closed subscriber group (CSG), the UEs 115associated with users in a home or office). A base station 105 maysupport one or multiple cells and may also support communications overthe one or more cells using one or multiple component carriers.

In some examples, a carrier may support multiple cells, and differentcells may be configured according to different protocol types (e.g.,MTC, narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB)) that mayprovide access for different types of devices.

In some examples, a base station 105 may be movable and thereforeprovide communication coverage for a moving geographic coverage area110. In some examples, different geographic coverage areas 110associated with different technologies may overlap, but the differentgeographic coverage areas 110 may be supported by the same base station105. In other examples, the overlapping geographic coverage areas 110associated with different technologies may be supported by differentbase stations 105. The wireless communications system 100 may include,for example, a heterogeneous network in which different types of thebase stations 105 provide coverage for various geographic coverage areas110 using the same or different radio access technologies.

Some UEs 115, such as MTC or IoT devices, may be low cost or lowcomplexity devices and may provide for automated communication betweenmachines (e.g., via Machine-to-Machine (M2M) communication). M2Mcommunication or MTC may refer to data communication technologies thatallow devices to communicate with one another or a base station 105without human intervention. In some examples, M2M communication or MTCmay include communications from devices that integrate sensors or metersto measure or capture information and relay such information to acentral server or application program that makes use of the informationor presents the information to humans interacting with the applicationprogram. Some UEs 115 may be designed to collect information or enableautomated behavior of machines or other devices. Examples ofapplications for MTC devices include smart metering, inventorymonitoring, water level monitoring, equipment monitoring, healthcaremonitoring, wildlife monitoring, weather and geological eventmonitoring, fleet management and tracking, remote security sensing,physical access control, and transaction-based business charging.

The wireless communications system 100 may be configured to supportultra-reliable communications or low-latency communications, or variouscombinations thereof. For example, the wireless communications system100 may be configured to support ultra-reliable low-latencycommunications (URLLC) or mission critical communications. The UEs 115may be designed to support ultra-reliable, low-latency, or criticalfunctions (e.g., mission critical functions). Ultra-reliablecommunications may include private communication or group communicationand may be supported by one or more mission critical services such asmission critical push-to-talk (MCPTT), mission critical video (MCVideo),or mission critical data (MCData). Support for mission criticalfunctions may include prioritization of services, and mission criticalservices may be used for public safety or general commercialapplications. The terms ultra-reliable, low-latency, mission critical,and ultra-reliable low-latency may be used interchangeably herein.

In some examples, a UE 115 may also be able to communicate directly withother UEs 115 over a device-to-device (D2D) communication link 135(e.g., using a peer-to-peer (P2P) or D2D protocol). One or more UEs 115utilizing D2D communications may be within the geographic coverage area110 of a base station 105. Other UEs 115 in such a group may be outsidethe geographic coverage area 110 of a base station 105 or be otherwiseunable to receive transmissions from a base station 105. In someexamples, groups of the UEs 115 communicating via D2D communications mayutilize a one-to-many (1:M) system in which each UE 115 transmits toevery other UE 115 in the group. In some examples, a base station 105facilitates the scheduling of resources for D2D communications. In othercases, D2D communications are carried out between the UEs 115 withoutthe involvement of a base station 105.

In some systems, the D2D communication link 135 may be an example of acommunication channel, such as a sidelink communication channel, betweenvehicles (e.g., UEs 115). In some examples, vehicles may communicateusing vehicle-to-everything (V2X) communications, vehicle-to-vehicle(V2V) communications, or some combination of these. A vehicle may signalinformation related to traffic conditions, signal scheduling, weather,safety, emergencies, or any other information relevant to a V2X system.In some examples, vehicles in a V2X system may communicate with roadsideinfrastructure, such as roadside units, or with the network via one ormore network nodes (e.g., base stations 105) using vehicle-to-network(V2N) communications, or with both.

The core network 130 may provide user authentication, accessauthorization, tracking, Internet Protocol (IP) connectivity, and otheraccess, routing, or mobility functions. The core network 130 may be anevolved packet core (EPC) or 5G core (5GC), which may include at leastone control plane entity that manages access and mobility (e.g., amobility management entity (MME), an access and mobility managementfunction (AMF)) and at least one user plane entity that routes packetsor interconnects to external networks (e.g., a serving gateway (S-GW), aPacket Data Network (PDN) gateway (P-GW), or a user plane function(UPF)). The control plane entity may manage non-access stratum (NAS)functions such as mobility, authentication, and bearer management forthe UEs 115 served by the base stations 105 associated with the corenetwork 130. User IP packets may be transferred through the user planeentity, which may provide IP address allocation as well as otherfunctions. The user plane entity may be connected to IP services 150 forone or more network operators. The IP services 150 may include access tothe Internet, Intranet(s), an IP Multimedia Subsystem (IMS), or aPacket-Switched Streaming Service.

Some of the network devices, such as a base station 105, may includesubcomponents such as an access network entity 140, which may be anexample of an access node controller (ANC). Each access network entity140 may communicate with the UEs 115 through one or more other accessnetwork transmission entities 145, which may be referred to as radioheads, smart radio heads, or transmission/reception points (TRPs). Eachaccess network transmission entity 145 may include one or more antennapanels. In some configurations, various functions of each access networkentity 140 or base station 105 may be distributed across various networkdevices (e.g., radio heads and ANCs) or consolidated into a singlenetwork device (e.g., a base station 105).

The wireless communications system 100 may operate using one or morefrequency bands, typically in the range of 300 megahertz (MHz) to 300gigahertz (GHz). Generally, the region from 300 MHz to 3 GHz is known asthe ultra-high frequency (UHF) region or decimeter band because thewavelengths range from approximately one decimeter to one meter inlength. The UHF waves may be blocked or redirected by buildings andenvironmental features, but the waves may penetrate structuressufficiently for a macro cell to provide service to the UEs 115 locatedindoors. The transmission of UHF waves may be associated with smallerantennas and shorter ranges (e.g., less than 100 kilometers) compared totransmission using the smaller frequencies and longer waves of the highfrequency (HF) or very high frequency (VHF) portion of the spectrumbelow 300 MHz.

The wireless communications system 100 may also operate in a super highfrequency (SHF) region using frequency bands from 3 GHz to 30 GHz, alsoknown as the centimeter band, or in an extremely high frequency (EHF)region of the spectrum (e.g., from 30 GHz to 300 GHz), also known as themillimeter band. In some examples, the wireless communications system100 may support millimeter wave (mmW) communications between the UEs 115and the base stations 105, and EHF antennas of the respective devicesmay be smaller and more closely spaced than UHF antennas. In someexamples, this may facilitate use of antenna arrays within a device. Thepropagation of EHF transmissions, however, may be subject to evengreater atmospheric attenuation and shorter range than SHF or UHFtransmissions. The techniques disclosed herein may be employed acrosstransmissions that use one or more different frequency regions, anddesignated use of bands across these frequency regions may differ bycountry or regulating body.

The wireless communications system 100 may utilize both licensed andunlicensed radio frequency spectrum bands. For example, the wirelesscommunications system 100 may employ License Assisted Access (LAA),LTE-Unlicensed (LTE-U) radio access technology, or NR technology in anunlicensed band such as the 5 GHz industrial, scientific, and medical(ISM) band. When operating in unlicensed radio frequency spectrum bands,devices such as the base stations 105 and the UEs 115 may employ carriersensing for collision detection and avoidance. In some examples,operations in unlicensed bands may be based on a carrier aggregationconfiguration in conjunction with component carriers operating in alicensed band (e.g., LAA). Operations in unlicensed spectrum may includedownlink transmissions, uplink transmissions, P2P transmissions, or D2Dtransmissions, among other examples.

A base station 105 or a UE 115 may be equipped with multiple antennas,which may be used to employ techniques such as transmit diversity,receive diversity, multiple-input multiple-output (MIMO) communications,or beamforming. The antennas of a base station 105 or a UE 115 may belocated within one or more antenna arrays or antenna panels, which maysupport MIMO operations or transmit or receive beamforming. For example,one or more base station antennas or antenna arrays may be co-located atan antenna assembly, such as an antenna tower. In some examples,antennas or antenna arrays associated with a base station 105 may belocated in diverse geographic locations. A base station 105 may have anantenna array with a number of rows and columns of antenna ports thatthe base station 105 may use to support beamforming of communicationswith a UE 115. Likewise, a UE 115 may have one or more antenna arraysthat may support various MIMO or beamforming operations. Additionally oralternatively, an antenna panel may support radio frequency beamformingfor a signal transmitted via an antenna port.

The base stations 105 or the UEs 115 may use MIMO communications toexploit multipath signal propagation and increase the spectralefficiency by transmitting or receiving multiple signals via differentspatial layers. Such techniques may be referred to as spatialmultiplexing. The multiple signals may, for example, be transmitted bythe transmitting device via different antennas or different combinationsof antennas. Likewise, the multiple signals may be received by thereceiving device via different antennas or different combinations ofantennas. Each of the multiple signals may be referred to as a separatespatial stream and may carry bits associated with the same data stream(e.g., the same codeword) or different data streams (e.g., differentcodewords). Different spatial layers may be associated with differentantenna ports used for channel measurement and reporting. MIMOtechniques include single-user MIMO (SU-MIMO), where multiple spatiallayers are transmitted to the same receiving device, and multiple-userMIMO (MU-MIMO), where multiple spatial layers are transmitted tomultiple devices.

Beamforming, which may also be referred to as spatial filtering,directional transmission, or directional reception, is a signalprocessing technique that may be used at a transmitting device or areceiving device (e.g., a base station 105, a UE 115) to shape or steeran antenna beam (e.g., a transmit beam, a receive beam) along a spatialpath between the transmitting device and the receiving device.Beamforming may be achieved by combining the signals communicated viaantenna elements of an antenna array such that some signals propagatingat particular orientations with respect to an antenna array experienceconstructive interference while others experience destructiveinterference. The adjustment of signals communicated via the antennaelements may include a transmitting device or a receiving deviceapplying amplitude offsets, phase offsets, or both to signals carriedvia the antenna elements associated with the device. The adjustmentsassociated with each of the antenna elements may be defined by abeamforming weight set associated with a particular orientation (e.g.,with respect to the antenna array of the transmitting device orreceiving device, or with respect to some other orientation).

A base station 105 or a UE 115 may use beam sweeping techniques as partof beam forming operations. For example, a base station 105 may usemultiple antennas or antenna arrays (e.g., antenna panels) to conductbeamforming operations for directional communications with a UE 115.Some signals (e.g., synchronization signals, reference signals, beamselection signals, or other control signals) may be transmitted by abase station 105 multiple times in different directions. For example,the base station 105 may transmit a signal according to differentbeamforming weight sets associated with different directions oftransmission. Transmissions in different beam directions may be used toidentify (e.g., by a transmitting device, such as a base station 105, orby a receiving device, such as a UE 115) a beam direction for latertransmission or reception by the base station 105.

Some signals, such as data signals associated with a particularreceiving device, may be transmitted by a base station 105 in a singlebeam direction (e.g., a direction associated with the receiving device,such as a UE 115). In some examples, the beam direction associated withtransmissions along a single beam direction may be determined based on asignal that was transmitted in one or more beam directions. For example,a UE 115 may receive one or more of the signals transmitted by the basestation 105 in different directions and may report to the base station105 an indication of the signal that the UE 115 received with a highestsignal quality or an otherwise acceptable signal quality.

In some examples, transmissions by a device (e.g., by a base station 105or a UE 115) may be performed using multiple beam directions, and thedevice may use a combination of digital precoding or radio frequencybeamforming to generate a combined beam for transmission (e.g., from abase station 105 to a UE 115). The UE 115 may report feedback thatindicates precoding weights for one or more beam directions, and thefeedback may correspond to a configured number of beams across a systembandwidth or one or more sub-bands. The base station 105 may transmit areference signal (e.g., a cell-specific reference signal (CRS), achannel state information reference signal (CSI-RS)), which may beprecoded or unprecoded. The UE 115 may provide feedback for beamselection, which may be a precoding matrix indicator (PMI) orcodebook-based feedback (e.g., a multi-panel type codebook, a linearcombination type codebook, a port selection type codebook). Althoughthese techniques are described with reference to signals transmitted inone or more directions by a base station 105, a UE 115 may employsimilar techniques for transmitting signals multiple times in differentdirections (e.g., for identifying a beam direction for subsequenttransmission or reception by the UE 115) or for transmitting a signal ina single direction (e.g., for transmitting data to a receiving device).

A receiving device (e.g., a UE 115) may try multiple receiveconfigurations (e.g., directional listening) when receiving varioussignals from the base station 105, such as synchronization signals,reference signals, beam selection signals, or other control signals. Forexample, a receiving device may try multiple receive directions byreceiving via different antenna subarrays, by processing receivedsignals according to different antenna subarrays, by receiving accordingto different receive beamforming weight sets (e.g., differentdirectional listening weight sets) applied to signals received atmultiple antenna elements of an antenna array, or by processing receivedsignals according to different receive beamforming weight sets appliedto signals received at multiple antenna elements of an antenna array,any of which may be referred to as “listening” according to differentreceive configurations or receive directions. In some examples, areceiving device may use a single receive configuration to receive alonga single beam direction (e.g., when receiving a data signal). The singlereceive configuration may be aligned in a beam direction determinedbased on listening according to different receive configurationdirections (e.g., a beam direction determined to have a highest signalstrength, highest signal-to-noise ratio (SNR), or otherwise acceptablesignal quality based on listening according to multiple beamdirections).

Additionally, a base station 105 in the wireless communications system100 may include one or more TRPs. Each TRP may be associated with one ormore antenna ports, beams, and beam indices. In some cases, a UE 115 maytransmit one or more uplink communications to multiple TRPs, and suchcommunications may include multiple repetitions of an uplinkcommunication to multiple TRPs to enhance the likelihood of successfulreceipt of the uplink communication. In some cases, the UE 115 maytransmit uplink communications based on parameters (e.g., a number ofantenna ports, a spatial domain filter or beam, a rank or number oflayers, or any combinations thereof) that are determined from SRSresources associated with the uplink communication. The SRS resourcesmay be selected from one or two sets of SRS resources that areconfigured at the UE 115, and may be indicated in control informationprovided to the UE 115.

FIG. 2 illustrates an example of a wireless communications system 200that supports rank and resource set signaling techniques for multipleTRP communications in accordance with aspects of the present disclosure.For example, the wireless communications system 200 includes basestations 105-a and 105-b, and a UE 115-a, which may be examples of therespective devices as described with reference to FIG. 1. It is to beunderstood that references to specific wireless devices (e.g., UEs,TRPs, base stations) in the below figures are provided for illustrativepurposes, and different wireless devices not specifically referred toherein may be used interchangeably with those described herein.Likewise, the described operations performed by a UE 115 may, in somecases, be performed by a base station 105 (or TRP), and vice versa. Insome examples, multiple TRPs may each be a standalone TRPs or may bepart of one base station 105 or different base stations 105.Additionally or alternatively, the base stations 105 or TRPs may be acomponent of or an example of an IAB node, a repeater node (e.g.,configured with some retransmission capability), or the like. Further,the UE 115-a may be an example of a customer premises equipment (CPE), asidelink node, a repeater node, or the like.

A first base station 105-a (e.g., that is associated with a first TRP)may provide coverage area 110-a, and a second base station 105-b (e.g.,that is associated with a second TRP) may provide coverage area 110-b.Additionally, each base station 105 may communicate with the UE 115-aover one or multiple communication links. For example, the first basestation 105-a may transmit downlink communications to the UE 115-a vialink 205, and the UE 115-a may transmit uplink communications to thefirst base station 105-a via link 210. In this example, the UE 115-a mayalso transmit uplink communications to the second base station 105-b vialink 215. In some examples, the base stations 105 and the UE 115-a maycommunicate using particular directional beams that are identified basedon one or more beam training procedures.

In some cases, in order to allow for more reliable uplink communicationsto both of the base stations 105 the UE 115-a may be configured with twoSRS resource sets. The SRS resources from one or both of the SRSresource sets may be indicated by a resource indication (e.g., one ormore SRI fields) transmitted to the UE 115-a in control information 225.In some cases, the UE 115-a may receive configuration information 220that configures multiple SRS resource sets, and that configures a numberof bits that are to be used to indicate whether one or multiple SRSresource sets are to be used and SRS resources within each SRS resourceset. For example, the configuration information 220 may be RRC signaledconfiguration information. The resource indication may provide anindication of a first mode in which one SRS resource set is to be usedfor an associated first uplink transmission 230 to the first basestation 105-a, and SRS resources within the one SRS resource set.Alternatively, the resource indication may provide an indication of asecond mode in which multiple SRS resource sets are to be used for anassociated first uplink transmission 230 to the first base station 105-aand second uplink transmission 235 to the second base station, alongwith the associated SRS resources within each SRS resource set.

In some cases, for dynamic indication of the first mode versus thesecond mode, by the control information 225 (e.g., DCI for non-codebookbased PUSCH), the number of bits needed to indicate SRS resources withinone (in the first mode) or two (in in the second mode) SRS resource setsthat are associated with the PUSCH repetitions may be determined as:1+max (X, Y). In some cases, one bit within the control information 225is to indicate the first mode (one SRS resource set) versus the secondmode (two SRS resource sets). For example, this bit can be the first bitof an SRI field of the control information 225, or can be a separatefield. The value X is the number of bits that are needed to indicate oneor more (up to L_(max)) SRS resources within one SRS resource set incase that the first mode is indicated, and the value of Y is the numberof bits that are needed to indicate one or more (up to L′_(max)) SRSresources within the first SRS resource set plus the number of bits thatare needed to indicate one or more (up to L′_(max)) SRS resources withinthe second SRS resource set in case that the second mode is indicated(where L′_(max)<L_(max)). In some cases, L′_(max) may be a fixed value(e.g., L′_(max)=1 if only single layer transmission is allowed for thesecond mode), or can be RRC configured, which may be also a function ofUE 115-a capability signaling.

In some cases, the size of the control information 225 may be alignedsuch that a same number of bits are used for signaling both the firstmode information and the second mode information. In some cases, forsize alignment, if X>Y (i. e., max(X, Y)=X) and the second mode isindicated (i.e., Y bits are needed), then zero-padding may be used, and(X−Y) zeros may be appended or prepended to the indication field in thecontrol information 225 (e.g., X−Y least significant bits or mostsignificant bits are set to zero). Alternatively, if Y>X (i.e., max(X,Y)=Y) and the first mode is indicated (i.e., X bits are needed), the(Y−X) zeros may be appended or prepended to the indication field in thecontrol information 225 (e.g., Y−X least significant bits or mostsignificant bits are set to zero).

In some cases, assuming that the first SRS resource set is configuredwith N_(SRS) ¹ SRS resources and the second SRS resource set isconfigured with N_(SRS) ²¹ SRS resources, the values X and Y may bedetermined as:

for X (number of bits to indicate one or more (up to L_(max)) SRSresources within one SRS resource set in case of the first mode):

-   -   Case 1: If the one SRS resource set is always the first SRS        resource set,

$X = {\left\lceil {\log_{2}{\sum\limits_{k = 1}^{\min{({L_{\max},N_{SRS}^{1}})}}\begin{pmatrix}N_{SRS}^{1} \\k\end{pmatrix}}} \right\rceil.}$

-   -   Case 2: If the one SRS resource set can be either the first SRS        resource set or the second SRS resource set,

${X = {1 + \left\lceil {\log_{2}{\sum\limits_{k = 1}^{{{mi}n}{({L_{\max},{\max{({N_{SRS}^{1},N_{SRS}^{2}})}}})}}\begin{pmatrix}{\max\left( {N_{SRS}^{1},N_{SRS}^{2}} \right)} \\K\end{pmatrix}}} \right\rceil}},$

where the 1 bit is to indicate either the first SRS resource set or thesecond SRS resource set, and max (N_(SRS) ¹, N_(SRS) ²) is because themaximum number needs to be considered if the SRS resource set withlarger number of SRS resources is indicated.

for Y (the number of bits to indicate one or more (up to L′_(max)) SRSresources within the first SRS resource set plus the number of bits toindicate one or more (up to L′_(max)) SRS resources within the secondSRS resource set in case of the second mode):

-   -   Case 1 (separate indication):

$Y = {\left\lceil {\log_{2}{\sum\limits_{k = 1}^{{{mi}n}{({L_{\max}^{\prime},N_{SRS}^{1}})}}\begin{pmatrix}N_{SRS}^{1} \\k\end{pmatrix}}} \right\rceil + \left\lceil {\log_{2}{\sum\limits_{k = 1}^{\min{({L_{\max}^{\prime},N_{SRS}^{2}})}}\;\begin{pmatrix}N_{SRS}^{2} \\k\end{pmatrix}}} \right\rceil}$

-   -   Case 2 (joint indication assuming that actual number of layers,        i.e., indicated number of SRS resources within each set, is the        same for both sets of repetitions):

$Y = {\left\lceil {\log_{2}{\sum\limits_{k = 1}^{\min{({L_{\max}^{\prime},N_{SRS}^{1},N_{SRS}^{2}})}}{\begin{pmatrix}N_{SRS}^{1} \\k\end{pmatrix}\begin{pmatrix}N_{SRS}^{2} \\k\end{pmatrix}}}} \right\rceil.}$

Alternatively, in some cases, a joint indication of one or two SRSresource sets along with indicated SRS resources of each SRS resourceset may be provided. In such cases, for dynamic indication of the firstmode versus the second mode (e.g., by the DCI for non-codebook basedPUSCH) as well as for indication of SRS resources within one (in thefirst mode) or two (in the second mode) SRS resource sets that areassociated with PUSCH repetitions, one SRI field may jointly coded toindicate one of the multiple possibilities, including:

Case 1 (one SRS resource set is always the first SRS resource set): Thenumber of bits needed is:

$\left\lceil {\log_{2}\left( {{\sum\limits_{k = 1}^{{{mi}n}{({L_{\max}^{\prime},N_{SRS}^{1}})}}\ \begin{pmatrix}N_{SRS}^{1} \\k\end{pmatrix}} + {\sum\limits_{k = 1}^{{{{mi}n}{({L_{\max}^{\prime},N_{SRS}^{1},N_{SRS}^{2}})}})}\ {\begin{pmatrix}N_{SRS}^{1} \\k\end{pmatrix}\begin{pmatrix}N_{SRS}^{2} \\k\end{pmatrix}}}} \right)} \right\rceil$

where the first term

$\left( {{i.e.},{\log_{2}\left( {\overset{\min{({L_{\max},N_{SRS}^{1}})}}{\sum\limits_{k = 1}}\ \begin{pmatrix}N_{SRS}^{1} \\k\end{pmatrix}} \right)}} \right.$

indicates the number of possibilities for the first mode to indicate SRSresources within the first SRS resource set, and the second termindicates the number of possibilities for the second mode to indicateSRS resources within both the first SRS resource set or the second SRSresource set, where the number of indicated SRS resources is the same(across first set and second set).Case 2 (one SRS resource set can be either the first set or the secondset): The number of bits needed is:

$\left\lceil {\log_{2}\left( {{\sum\limits_{k = 1}^{{{mi}n}{({L_{\max},N_{SRS}^{1}})}}\ \begin{pmatrix}N_{SRS}^{1} \\k\end{pmatrix}} + {\overset{\min{({L_{\max},N_{SRS}^{2}})}}{\sum\limits_{k = 1}}\ \begin{pmatrix}N_{SRS}^{1} \\k\end{pmatrix}} + {\sum\limits_{k = 1}^{{{mi}n}{({L_{\max}^{\prime},N_{SRS}^{1},N_{SRS}^{2}})}}\ {\begin{pmatrix}N_{SRS}^{1} \\k\end{pmatrix}\begin{pmatrix}N_{SRS}^{2} \\k\end{pmatrix}}}} \right)} \right\rceil$

where the first two terms indicate the number of possibilities for thefirst mode to indicate SRS resources within either the first SRSresource set or the second SRS resource set, and the third termindicates the number of possibilities for the second mode to indicateSRS resources within both the first SRS resource set or the second SRSresource set, where the number of indicated SRS resources is the same(across first set and second set). Using such techniques, each codepointof the joint fields is mapped to one of the possibilities of SRSresource sets to use and indicated SRS resources of each set.

For example, assume N_(SRS) ¹=4, N_(SRS) ²=4, L_(max)=4, L′_(max)=1. Ifseparate SRI fields were simply transmitted, 8 bits are needed for twoSRI fields each with 4 bits.

In cases where joint coding is not used, assuming Case 2 for X andeither Casel/Case2 (same result in this example) for Y, 6 bits areneeded:

$\begin{matrix}{{X = {{1 + \left\lceil {\log_{2}{\sum\limits_{k = 1}^{4}\begin{pmatrix}4 \\k\end{pmatrix}}} \right\rceil} = {{1 + 4} = 5}}}{Y = {{\left\lceil {\log_{2}\begin{pmatrix}4 \\1\end{pmatrix}} \right\rceil + \left\lceil {\log_{2}\begin{pmatrix}4 \\1\end{pmatrix}} \right\rceil} = {\left. 4\rightarrow{1 + {\max\left( {X,\ Y} \right)}} \right. = {{1 + 5} = {6.}}}}}} & (41)\end{matrix}$

Assuming Case 1 for X and either Case1/Case2 (same result in thisexample) for Y, 5 bits are needed:

$X = {\left\lceil {\log_{2}{\sum\limits_{k = 1}^{4}\begin{pmatrix}4 \\k\end{pmatrix}}} \right\rceil = 4}$

In cases where joint coding is used, 6 bits are needed:

$\begin{matrix}{\left\lceil {\log_{2}\left( {{\sum\limits_{k = 1}^{4}\begin{pmatrix}4 \\k\end{pmatrix}} + {\sum\limits_{k = 1}^{4}\begin{pmatrix}4 \\k\end{pmatrix}} + {\begin{pmatrix}4 \\1\end{pmatrix}\begin{pmatrix}4 \\1\end{pmatrix}}} \right)} \right\rceil = {\left\lceil {\log_{2}\left( {{15} + {15} + {16}} \right)} \right\rceil = 6}} & (41)\end{matrix}$

Assuming Case 1: 5 bits are needed

$\begin{matrix}{\left\lceil {\log_{2}\left( {{\sum\limits_{k = 1}^{4}\begin{pmatrix}4 \\k\end{pmatrix}} + {\begin{pmatrix}4 \\1\end{pmatrix}\begin{pmatrix}4 \\1\end{pmatrix}}} \right)} \right\rceil = {\left\lceil {\log_{2}\left( {{15} + {16}} \right)} \right\rceil = {5.}}} & (41)\end{matrix}$

In another example, assume N_(SRS) ¹=4, N_(SRS) ²=4, L_(max)=4,L′_(max)=1. If separate SRI fields were simply transmitted, 7 bits areneeded (two SRI fields, first one with 4 bits; second one with 3 bits).In cases where joint coding is not used, assuming Case2 (for both X andY): 1+max(X, Y)=1+max(1+4,4)=6 bits are needed. In cases where jointcoding is used, assuming Case2:

┌log₂(Σ_(k=1) ²(_(k) ⁴)+Σ_(k=1) ²(_(k) ³)+(₁ ⁴)(₁ ³)┐=5 bits are needed.Accordingly, using techniques as discussed herein, signaling overheadmay be reduced relative to transmission is separate SRI fields for DCItransmissions.

FIG. 3 illustrates an example of control and shared channelcommunications 300 that support rank and resource set signalingtechniques for multiple TRP communications in accordance with aspects ofthe present disclosure. For example, control and shared channelcommunications 300 may be used in wireless communications systems thatinclude UEs 115 and base stations 105 as described with reference toFIGS. 1 and 2. It is to be understood that references to specificwireless devices (e.g., UEs, TRPs, base stations) in the exemplaryfigures are provided for illustrative purposes, and different wirelessdevices not specifically referred to herein may be used interchangeablywith those described herein. Likewise, the described operationsperformed by a UE 115 may, in some cases, be performed by a base station105, and vice versa. In some examples, the base stations may be examplesof, or include, one or more TRPs. Additionally or alternatively, thebase stations may each be an example of an IAB node, a repeater node(e.g., configured with some retransmission capability), or the like.Further, the UEs may be examples of a CPE, a sidelink node, a repeaternode, or the like.

In this example, a scheduling DCI 305 may schedule an uplinktransmission that has a first set of repetitions 310 and a second set ofrepetitions 315. Further, the first set of repetitions 310 may include afirst repetition 310-a and a second repetition 310-b that are bothtransmitted to a first TRP. Likewise, the second set of repetitions 315may include a third repetition 315-a and a fourth repetition 315-b thatare both transmitted to a second TRP. Each repetition of both the firstset of repetitions 310 and the second set of repetitions 315 may includea same TB, and thus the multiple repetitions to the multiple differentTRPs may enhance the likelihood of successful decoding of the TB ateither or both of the first and second TRPs. As discussed herein, thescheduling DCI 305 may include a resource indication field thatindicates whether one or two SRS resource sets are used, as well as SRSresource within each SRS resource set, as discussed with reference toFIG. 2.

FIG. 4 illustrates an example of control information 400 that supportsrank and resource set signaling techniques for multiple TRPcommunications in accordance with aspects of the present disclosure. Forexample, the control information 400 may be used in wirelesscommunications systems that include UEs 115 and base stations 105 asdescribed herein.

In this example, an uplink DCI 405 may include scheduling informationfor an uplink PUSCH communication from a UE to one or multiple TRPs. Inthis example, the UE may be configured (e.g., via RRC signaling) withtwo SRS resource sets, including a first SRS resource set 415 and asecond SRS resource set 420. Further, the UE may be configured to expectcontrol information in a SRI field 410 that indicates whether one orboth SRS resource sets are to be used for the associated uplinkcommunication, and SRS resources within each indicated SRS resource set.In accordance with techniques provided herein, the uplink DCI 405 andthe SRI field 410 may provide related SRS indications as discussed withreference to FIG. 2.

In this example, the first SRS resource set 415 may be configured withfour SRS resources that include a first SRS resource 425-a, a second SRSresource 425-b, a third SRS resource 425-c, and a fourth SRS resource425-d. Similarly, the second SRS resource set 420 may be configured withfour SRS resources that include a first SRS resource 430-a, a second SRSresource 430-b, a third SRS resource 430-c, and a fourth SRS resource430-d. The SRI field 410 in this example indicates (e.g., as discussedwith reference to FIG. 2), within the first SRS resource set 415, thefirst SRS resource 425-a and the third SRS resource 425-c, and withinthe second SRS resource set 420, the second SRS resource 430-b and thethird SRS resource 430-c. Thus, in this example, the uplinkcommunication may be transmitted in a first repetition that uses uplinktransmission parameters that are suitable for transmissions to a firstTRP using a first beam and in a second repetition that uses uplinktransmission parameters that are suitable for transmissions to a secondTRP using a second beam.

FIG. 5 illustrates an example of a process flow 500 that supports rankand resource set signaling techniques for multiple TRP communications inaccordance with aspects of the present disclosure. In some examples, theprocess flow 500 may implement aspects of wireless communicationssystems 100 or 200. For example, the process flow 500 includes a UE115-b and base stations 105-c and 105-d that each may be examples of thecorresponding devices described with reference to FIGS. 1-4. The processflow 500 may illustrate an example of the base stations 105-c and 105-dand the UE 115-b determining uplink transmission parameters (e.g., basedon rank and SRS resources) for multiple repetitions of an uplinkcommunication to different TRPs.

In the following description of the process flow 500, the operationsbetween the UE 115-b and the base stations 105-c and 105-d may betransmitted in a different order than the order shown, or the operationsperformed by the base stations 105-c and 105-d and the UE 115-b may beperformed in different orders or at different times. Certain operationsmay also be left out of the process flow 500, or other operations may beadded to the process flow 500. It is to be understood that while basestations 105-c and 105-d and the UE 115-b are shown performing a numberof the operations of process flow 500, any wireless device (e.g., a UE,a CPE, a base station, a transmission/reception point (TRP), an IABnode, a repeater with different types of capabilities in terms ofrepetition of signals (also known as “smart” or “dumb” repeaters, orsome other terminology), or a sidelink node, among other examples) mayperform the operations shown.

Optionally, at 505, the UE 115-b may transmit a capability indication tothe first base station 105-c (e.g., which may include a first TRP). Sucha capability indication may provide information related to whether theUE 115-b is capable of receiving control information and configurationinformation that provides for uplink transmissions to multiple TRPsusing different uplink transmission parameters that are scheduled with asame scheduling DCI.

At 510, the first base station 105-c may determine configurationinformation for the UE 115-b. In some cases, the first base station105-c may be a serving base station 105-c, and may determine that the UE115-b is to transmit multiple repetitions of uplink communications. Insome cases, the configuration information may include configuration ofmultiple SRS resource sets, which may each be associated with differentTRPs (e.g., a first SRS resource set may provide SRS resources that aresuitable for communications with one or multiple TRPs, and a second SRSresource set may provide SRS resources that are suitable forcommunications with one or multiple TRPs that may include some or noneof the same TRPs as the first SRS resource set). The configurationinformation may also include an indication of a format (e.g., a numberof bits) of control information that schedules uplink communications(e.g., such as discussed with reference to FIG. 2). Additionally, insome cases, the configuration information may also configure one of theSRS resource sets as being associated with a particular SRI field incontrol information. In some cases, the first base station 105-c mayoptionally exchange TRP coordination information with the second basestation 105-d, as indicated at 515. Such coordination information mayinclude information on uplink resources for expected uplinkcommunications, for example.

At 520, the first base station 105-c may transmit SRS resourceconfiguration to the UE 115-b. In some cases, the SRS resourceconfiguration may be transmitted as part of RRC signaling between the UE115-b and the first base station 105-c. At 525, the first base station105-c may determine a repetition level, SRS resources, and an uplinkallocation, for an uplink communication from the UE 115-b.

At 530, the first base station 105-c (and/or optionally the second basestation 105-d) may transmit DCI to the UE 115-b. The DCI may include anindication (e.g., as discussed with reference to FIG. 2) of whether oneor two SRS resource set(s) are to be used for an uplink communication, anumber of repetitions of the uplink communication, an indication of oneor more SRS resources within the one or more SRS resource sets that areassociate with the uplink communication, or any combinations thereof.

At 535, the UE 115-b may determine (e.g., as discussed with reference toFIG. 2) uplink transmission parameters for repetitions of the uplinkcommunication. In some cases, the UE 115-b may determine which SRSresource of the configured SRS resource sets are to be associated withthe uplink communication, such as by using one or more techniques asdiscussed herein.

Optionally, at 540, the UE 115-b may transmit one or more SRSs to thefirst base station 105-c and/or the second base station 105-d. The oneor more SRSs may have uplink transmission parameters that are determinedbased on the indicated SRS resources, as discussed herein. At 545, theUE 115-b may transmit a first PUSCH to the first base station 105-c, andat 550 the UE 115-b may transmit a second PUSCH to the second basestation 105-d. The repetitions of the PUSCH may have uplink transmissionparameters that are determined based on the indicated SRS resources,such as by using various different techniques as provided herein.

FIG. 6 shows a block diagram 600 of a device 605 that supports rank andresource set signaling techniques for multiple TRP communications inaccordance with aspects of the present disclosure. The device 605 may bean example of aspects of a UE 115 as described herein. The device 605may include a receiver 610, a transmitter 615, and a communicationsmanager 620. The device 605 may also include a processor. Each of thesecomponents may be in communication with one another (e.g., via one ormore buses).

The receiver 610 may provide a means for receiving information such aspackets, user data, control information, or any combination thereofassociated with various information channels (e.g., control channels,data channels, information channels related to rank and resource setsignaling techniques for multiple TRP communications). Information maybe passed on to other components of the device 605. The receiver 610 mayutilize a single antenna or a set of multiple antennas.

The transmitter 615 may provide a means for transmitting signalsgenerated by other components of the device 605. For example, thetransmitter 615 may transmit information such as packets, user data,control information, or any combination thereof associated with variousinformation channels (e.g., control channels, data channels, informationchannels related to rank and resource set signaling techniques formultiple TRP communications). In some examples, the transmitter 615 maybe co-located with a receiver 610 in a transceiver module. Thetransmitter 615 may utilize a single antenna or a set of multipleantennas.

The communications manager 620, the receiver 610, the transmitter 615,or various combinations thereof or various components thereof may beexamples of means for performing various aspects of rank and resourceset signaling techniques for multiple TRP communications as describedherein. For example, the communications manager 620, the receiver 610,the transmitter 615, or various combinations or components thereof maysupport a method for performing one or more of the functions describedherein.

In some examples, the communications manager 620, the receiver 610, thetransmitter 615, or various combinations or components thereof may beimplemented in hardware (e.g., in communications management circuitry).The hardware may include a processor, a digital signal processor (DSP),an application-specific integrated circuit (ASIC), a field-programmablegate array (FPGA) or other programmable logic device, a discrete gate ortransistor logic, discrete hardware components, or any combinationthereof configured as or otherwise supporting a means for performing thefunctions described in the present disclosure. In some examples, aprocessor and memory coupled with the processor may be configured toperform one or more of the functions described herein (e.g., byexecuting, by the processor, instructions stored in the memory).

Additionally or alternatively, in some examples, the communicationsmanager 620, the receiver 610, the transmitter 615, or variouscombinations or components thereof may be implemented in code (e.g., ascommunications management software or firmware) executed by a processor.If implemented in code executed by a processor, the functions of thecommunications manager 620, the receiver 610, the transmitter 615, orvarious combinations or components thereof may be performed by ageneral-purpose processor, a DSP, a central processing unit (CPU), anASIC, an FPGA, or any combination of these or other programmable logicdevices (e.g., configured as or otherwise supporting a means forperforming the functions described in the present disclosure).

In some examples, the communications manager 620 may be configured toperform various operations (e.g., receiving, monitoring, transmitting)using or otherwise in cooperation with the receiver 610, the transmitter615, or both. For example, the communications manager 620 may receiveinformation from the receiver 610, send information to the transmitter615, or be integrated in combination with the receiver 610, thetransmitter 615, or both to receive information, transmit information,or perform various other operations as described herein.

The communications manager 620 may support wireless communication at thedevice 605 (e.g., a UE 115) in accordance with examples as disclosedherein. For example, the communications manager 620 may be configured asor otherwise support a means for receiving, from a base station, acontrol information configuration that indicates a quantity of bits thatare to be included in a control information field that indicates one ortwo SRS resource sets with which a first uplink communication is to beassociated. The communications manager 620 may be configured as orotherwise support a means for receiving, from the base station, a firstcontrol information communication that includes the control informationfield and that schedules the first uplink communication for the device605. The communications manager 620 may be configured as or otherwisesupport a means for determining, based on the first control informationcommunication and the control information configuration, whether one ortwo SRS resource sets are associated with the first uplinkcommunication. The communications manager 620 may be configured as orotherwise support a means for transmitting the first uplinkcommunication to the base station based on the determining.

By including or configuring the communications manager 620 in accordancewith examples as described herein, the device 605 (e.g., a processorcontrolling or otherwise coupled to the receiver 610, the transmitter615, the communications manager 620, or a combination thereof) maysupport techniques for transmitting multiple repetitions of an uplinkcommunication to multiple different TRPs, such that the differentrepetitions may use transmission parameters that are suitable for theparticular TRP associated with the repetition. Such techniques may allowfor enhanced reliability of wireless communications, and thus providemore efficient utilization of communication resources, reduced powerconsumption (through reduced retransmissions), reduced latency (throughreduced retransmission), and more efficient utilization of communicationresources.

FIG. 7 shows a block diagram 700 of a device 705 that supports rank andresource set signaling techniques for multiple TRP communications inaccordance with aspects of the present disclosure. The device 705 may bean example of aspects of a device 605 or a UE 115 as described herein.The device 705 may include a receiver 710, a transmitter 715, and acommunications manager 720. The device 705 may also include a processor.Each of these components may be in communication with one another (e.g.,via one or more buses).

The receiver 710 may provide a means for receiving information such aspackets, user data, control information, or any combination thereofassociated with various information channels (e.g., control channels,data channels, information channels related to rank and resource setsignaling techniques for multiple TRP communications). Information maybe passed on to other components of the device 705. The receiver 710 mayutilize a single antenna or a set of multiple antennas.

The transmitter 715 may provide a means for transmitting signalsgenerated by other components of the device 705. For example, thetransmitter 715 may transmit information such as packets, user data,control information, or any combination thereof associated with variousinformation channels (e.g., control channels, data channels, informationchannels related to rank and resource set signaling techniques formultiple TRP communications). In some examples, the transmitter 715 maybe co-located with a receiver 710 in a transceiver module. Thetransmitter 715 may utilize a single antenna or a set of multipleantennas.

The device 705, or various components thereof, may be an example ofmeans for performing various aspects of rank and resource set signalingtechniques for multiple TRP communications as described herein. Forexample, the communications manager 720 may include an SRS configurationmanager 725, a control information manager 730, an SRS resource setmanager 735, an uplink communication manager 740, or any combinationthereof The communications manager 720 may be an example of aspects of acommunications manager 620 as described herein. In some examples, thecommunications manager 720, or various components thereof, may beconfigured to perform various operations (e.g., receiving, monitoring,transmitting) using or otherwise in cooperation with the receiver 710,the transmitter 715, or both. For example, the communications manager720 may receive information from the receiver 710, send information tothe transmitter 715, or be integrated in combination with the receiver710, the transmitter 715, or both to receive information, transmitinformation, or perform various other operations as described herein.

The communications manager 720 may support wireless communication at thedevice 705 (e.g., a UE 115) in accordance with examples as disclosedherein. The SRS configuration manager 725 may be configured as orotherwise support a means for receiving, from a base station, a controlinformation configuration that indicates a quantity of bits that are tobe included in a control information field that indicates one or two SRSresource sets with which a first uplink communication is to beassociated. The control information manager 730 may be configured as orotherwise support a means for receiving, from the base station, a firstcontrol information communication that includes the control informationfield and that schedules the first uplink communication for the device705. The SRS resource set manager 735 may be configured as or otherwisesupport a means for determining, based on the first control informationcommunication and the control information configuration, whether one ortwo SRS resource sets are associated with the first uplinkcommunication. The uplink communication manager 740 may be configured asor otherwise support a means for transmitting the first uplinkcommunication to the base station based on the determining.

FIG. 8 shows a block diagram 800 of a communications manager 820 thatsupports rank and resource set signaling techniques for multiple TRPcommunications in accordance with aspects of the present disclosure. Thecommunications manager 820 may be an example of aspects of acommunications manager 620, a communications manager 720, or both, asdescribed herein. The communications manager 820, or various componentsthereof, may be an example of means for performing various aspects ofrank and resource set signaling techniques for multiple TRPcommunications as described herein. For example, the communicationsmanager 820 may include an SRS configuration manager 825, a controlinformation manager 830, an SRS resource set manager 835, an uplinkcommunication manager 840, a mapping manager 845, or any combinationthereof. Each of these components may communicate, directly orindirectly, with one another (e.g., via one or more buses).

The communications manager 820 may support wireless communication at thedevice 805 (e.g., a UE 115) in accordance with examples as disclosedherein. The SRS configuration manager 825 may be configured as orotherwise support a means for receiving, from a base station, a controlinformation configuration that indicates a quantity of bits that are tobe included in a control information field that indicates one or two SRSresource sets with which a first uplink communication is to beassociated. The control information manager 830 may be configured as orotherwise support a means for receiving, from the base station, a firstcontrol information communication that includes the control informationfield and that schedules the first uplink communication for the device805. The SRS resource set manager 835 may be configured as or otherwisesupport a means for determining, based on the first control informationcommunication and the control information configuration, whether one ortwo SRS resource sets are associated with the first uplinkcommunication. The uplink communication manager 840 may be configured asor otherwise support a means for transmitting the first uplinkcommunication to the base station based on the determining.

In some examples, to support determining, the SRS resource set manager835 may be configured as or otherwise support a means for determining,based on the first control information communication and the controlinformation configuration, the number of SRS resources for each SRSresource set associated with the first uplink communication.

In some examples, to support determining, the control informationmanager 830 may be configured as or otherwise support a means fordetermining, based on a first bit of the first control informationcommunication, whether one or two SRS resource sets are associated withthe first uplink communication, and where the control information fieldincludes a set of bits that indicate a number of SRS resources for eachSRS resource set associated with the first uplink communication. In someexamples, the first bit is an initial bit of the control informationfield, or is in a separate field in the first control informationcommunication. In some examples, the set of bits includes a maximum of afirst number of bits or a second number of bits, the first number ofbits determined based on a first maximum rank when one SRS resource setis associated with the first uplink communication, and the second numberof bits determined based on a second maximum rank when two SRS resourcesets are associated with the first uplink communication. In someexamples, the second maximum rank is less than the first maximum rank.In some examples, the second maximum rank is a fixed value or aconfigured value that is provided with the control informationconfiguration. In some examples, the configured value of the secondmaximum rank is based on a capability of the device 805 that istransmitted to the base station. In some examples, zero-padding is usedin the set of bits when a number of bits necessary to indicate the rankof the one or two SRS resource sets is less than a total number of bitsof the set of bits.

In some examples, the first number of bits is determined based on thefirst SRS resource set having a different number of SRS resources thanthe second SRS resource set. In some examples, the first number of bitsis associated with the first SRS resource set. In some examples, thefirst number of bits is associated with either the first SRS resourceset or the second SRS resource set, and a separate bit in the controlinformation field provides an indication of which of the first SRSresource set or the second SRS resource set is associated with the firstuplink communication. In some examples, the second number of bits isassociated with both the first SRS resource set and the second SRSresource set, and a first subset of the second number of bits indicatesone or more SRS resources within the first SRS resource set and a secondsubset of the second number of bits indicates one or more SRS resourceswithin the second SRS resource set. In some examples, the second numberof bits is associated with both the first SRS resource set and thesecond SRS resource set, and provides a joint indication of one or moreSRS resources within each of the SRS resource sets based on a samenumber of layers associated with each SRS resource set.

In some examples, to support determining, the mapping manager 845 may beconfigured as or otherwise support a means for decoding the controlinformation field to identify a set of bits. In some examples, tosupport determining, the mapping manager 845 may be configured as orotherwise support a means for identifying, based on a mapping for theset of bits, a number of SRS resources for each SRS resource setassociated with the first uplink communication.

In some examples, a first SRS resource set is ordered ahead of a secondSRS resource set, and the quantity of bits that are included in thecontrol information field is determined as a sum of a first number ofpossibilities to indicate a first number of SRS resources associatedwith the first SRS resource set when a single SRS resource set isassociated with the first uplink communication, and a second number ofpossibilities to indicate a second number of SRS resources associatedwith both the first and the second SRS resource set when both the firstSRS resource set and the second SRS resource set are associated with thefirst uplink communication.

In some examples, a first SRS resource set or a second SRS resource setis ordered as an initial SRS resource set. In some examples, where thequantity of bits that are included in the control information field isdetermined as a sum of a first number of possibilities to indicate afirst number of SRS resources associated with the initial SRS resourceset when a single SRS resource set is associated with the first uplinkcommunication, and a second number of possibilities to indicate a secondnumber of SRS resources associated with both the first and the secondSRS resource set when a both the first SRS resource set and the secondSRS resource set are associated with the first uplink communication. Insome examples, different bit values of the control information field aremapped to different possibilities of a number of the SRS resources thatare associated with the first uplink communication.

FIG. 9 shows a diagram of a system 900 including a device 905 thatsupports rank and resource set signaling techniques for multiple TRPcommunications in accordance with aspects of the present disclosure. Thedevice 905 may be an example of or include the components of a device605, a device 705, or a UE 115 as described herein. The device 905 maycommunicate wirelessly with one or more base stations 105, UEs 115, orany combination thereof. The device 905 may include components forbi-directional voice and data communications including components fortransmitting and receiving communications, such as a communicationsmanager 920, an input/output (I/O) controller 910, a transceiver 915, anantenna 925, a memory 930, code 935, and a processor 940. Thesecomponents may be in electronic communication or otherwise coupled(e.g., operatively, communicatively, functionally, electronically,electrically) via one or more buses (e.g., a bus 945).

The I/O controller 910 may manage input and output signals for thedevice 905. The I/O controller 910 may also manage peripherals notintegrated into the device 905. In some cases, the I/O controller 910may represent a physical connection or port to an external peripheral.In some cases, the I/O controller 910 may utilize an operating systemsuch as iOS®, ANDROID®, MS-DOS®, MS-WINDOWS®, OS/2®, UNIX®, LINUX®, oranother known operating system. Additionally or alternatively, the I/Ocontroller 910 may represent or interact with a modem, a keyboard, amouse, a touchscreen, or a similar device. In some cases, the I/Ocontroller 910 may be implemented as part of a processor, such as theprocessor 940. In some cases, a user may interact with the device 905via the I/O controller 910 or via hardware components controlled by theI/O controller 910.

In some cases, the device 905 may include a single antenna 925. However,in some other cases, the device 905 may have more than one antenna 925,which may be capable of concurrently transmitting or receiving multiplewireless transmissions. The transceiver 915 may communicatebi-directionally, via the one or more antennas 925, wired, or wirelesslinks as described herein. For example, the transceiver 915 mayrepresent a wireless transceiver and may communicate bi-directionallywith another wireless transceiver. The transceiver 915 may also includea modem to modulate the packets, to provide the modulated packets to oneor more antennas 925 for transmission, and to demodulate packetsreceived from the one or more antennas 925. The transceiver 915, or thetransceiver 915 and one or more antennas 925, may be an example of atransmitter 615, a transmitter 715, a receiver 610, a receiver 710, orany combination thereof or component thereof, as described herein.

The memory 930 may include random access memory (RAM) and read-onlymemory (ROM). The memory 930 may store computer-readable,computer-executable code 935 including instructions that, when executedby the processor 940, cause the device 905 to perform various functionsdescribed herein. The code 935 may be stored in a non-transitorycomputer-readable medium such as system memory or another type ofmemory. In some cases, the code 935 may not be directly executable bythe processor 940 but may cause a computer (e.g., when compiled andexecuted) to perform functions described herein. In some cases, thememory 930 may contain, among other things, a basic I/O system (BIOS)which may control basic hardware or software operation such as theinteraction with peripheral components or devices.

The processor 940 may include an intelligent hardware device (e.g., ageneral-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, anFPGA, a programmable logic device, a discrete gate or transistor logiccomponent, a discrete hardware component, or any combination thereof).In some cases, the processor 940 may be configured to operate a memoryarray using a memory controller. In some other cases, a memorycontroller may be integrated into the processor 940. The processor 940may be configured to execute computer-readable instructions stored in amemory (e.g., the memory 930) to cause the device 905 to perform variousfunctions (e.g., functions or tasks supporting rank and resource setsignaling techniques for multiple TRP communications). For example, thedevice 905 or a component of the device 905 may include a processor 940and memory 930 coupled to the processor 940, the processor 940 andmemory 930 configured to perform various functions described herein.

The communications manager 920 may support wireless communication at thedevice 905 (e.g., a UE 115) in accordance with examples as disclosedherein. For example, the communications manager 920 may be configured asor otherwise support a means for receiving, from a base station, acontrol information configuration that indicates a quantity of bits thatare to be included in a control information field that indicates one ortwo SRS resource sets with which a first uplink communication is to beassociated. The communications manager 920 may be configured as orotherwise support a means for receiving, from the base station, a firstcontrol information communication that includes the control informationfield and that schedules the first uplink communication for the device905. The communications manager 920 may be configured as or otherwisesupport a means for determining, based on the first control informationcommunication and the control information configuration, whether one ortwo SRS resource sets are associated with the first uplinkcommunication. The communications manager 920 may be configured as orotherwise support a means for transmitting the first uplinkcommunication to the base station based on the determining.

By including or configuring the communications manager 920 in accordancewith examples as described herein, the device 905 may support techniquesfor transmitting multiple repetitions of an uplink communication tomultiple different TRPs, such that the different repetitions may usetransmission parameters that are suitable for the particular TRPassociated with the repetition. Such techniques may allow for enhancedreliability of wireless communications, and thus provide more efficientutilization of communication resources, reduced power consumption(through reduced retransmissions), reduced latency (through reducedretransmission), and more efficient utilization of communicationresources.

In some examples, the communications manager 920 may be configured toperform various operations (e.g., receiving, monitoring, transmitting)using or otherwise in cooperation with the transceiver 915, the one ormore antennas 925, or any combination thereof. Although thecommunications manager 920 is illustrated as a separate component, insome examples, one or more functions described with reference to thecommunications manager 920 may be supported by or performed by theprocessor 940, the memory 930, the code 935, or any combination thereof.For example, the code 935 may include instructions executable by theprocessor 940 to cause the device 905 to perform various aspects of rankand resource set signaling techniques for multiple TRP communications asdescribed herein, or the processor 940 and the memory 930 may beotherwise configured to perform or support such operations.

FIG. 10 shows a block diagram 1000 of a device 1005 that supports rankand resource set signaling techniques for multiple TRP communications inaccordance with aspects of the present disclosure. The device 1005 maybe an example of aspects of a base station 105 as described herein. Thedevice 1005 may include a receiver 1010, a transmitter 1015, and acommunications manager 1020. The device 1005 may also include aprocessor. Each of these components may be in communication with oneanother (e.g., via one or more buses).

The receiver 1010 may provide a means for receiving information such aspackets, user data, control information, or any combination thereofassociated with various information channels (e.g., control channels,data channels, information channels related to rank and resource setsignaling techniques for multiple TRP communications). Information maybe passed on to other components of the device 1005. The receiver 1010may utilize a single antenna or a set of multiple antennas.

The transmitter 1015 may provide a means for transmitting signalsgenerated by other components of the device 1005. For example, thetransmitter 1015 may transmit information such as packets, user data,control information, or any combination thereof associated with variousinformation channels (e.g., control channels, data channels, informationchannels related to rank and resource set signaling techniques formultiple TRP communications). In some examples, the transmitter 1015 maybe co-located with a receiver 1010 in a transceiver module. Thetransmitter 1015 may utilize a single antenna or a set of multipleantennas.

The communications manager 1020, the receiver 1010, the transmitter1015, or various combinations thereof or various components thereof maybe examples of means for performing various aspects of rank and resourceset signaling techniques for multiple TRP communications as describedherein. For example, the communications manager 1020, the receiver 1010,the transmitter 1015, or various combinations or components thereof maysupport a method for performing one or more of the functions describedherein.

In some examples, the communications manager 1020, the receiver 1010,the transmitter 1015, or various combinations or components thereof maybe implemented in hardware (e.g., in communications managementcircuitry). The hardware may include a processor, a DSP, an ASIC, anFPGA or other programmable logic device, a discrete gate or transistorlogic, discrete hardware components, or any combination thereofconfigured as or otherwise supporting a means for performing thefunctions described in the present disclosure. In some examples, aprocessor and memory coupled with the processor may be configured toperform one or more of the functions described herein (e.g., byexecuting, by the processor, instructions stored in the memory).

Additionally or alternatively, in some examples, the communicationsmanager 1020, the receiver 1010, the transmitter 1015, or variouscombinations or components thereof may be implemented in code (e.g., ascommunications management software or firmware) executed by a processor.If implemented in code executed by a processor, the functions of thecommunications manager 1020, the receiver 1010, the transmitter 1015, orvarious combinations or components thereof may be performed by ageneral-purpose processor, a DSP, a CPU, an ASIC, an FPGA, or anycombination of these or other programmable logic devices (e.g.,configured as or otherwise supporting a means for performing thefunctions described in the present disclosure).

In some examples, the communications manager 1020 may be configured toperform various operations (e.g., receiving, monitoring, transmitting)using or otherwise in cooperation with the receiver 1010, thetransmitter 1015, or both. For example, the communications manager 1020may receive information from the receiver 1010, send information to thetransmitter 1015, or be integrated in combination with the receiver1010, the transmitter 1015, or both to receive information, transmitinformation, or perform various other operations as described herein.

The communications manager 1020 may support wireless communication atthe device 1005 (e.g., a base station 105) in accordance with examplesas disclosed herein. For example, the communications manager 1020 may beconfigured as or otherwise support a means for transmitting, to a UE, acontrol information configuration that indicates a quantity of bits thatare to be included in a control information field that indicates one ortwo SRS resource sets with which a first uplink communication is to beassociated. The communications manager 1020 may be configured as orotherwise support a means for determining whether one SRS resource setor two SRS resource sets are associated with the first uplinkcommunication. The communications manager 1020 may be configured as orotherwise support a means for transmitting, to the UE, a first controlinformation communication that includes the control information fieldand that schedules the first uplink communication for the UE andindicates whether one SRS resource set or two SRS resource sets areassociated with the first uplink communication. The communicationsmanager 1020 may be configured as or otherwise support a means forreceiving the first uplink communication from the UE based on the firstcontrol information communication.

By including or configuring the communications manager 1020 inaccordance with examples as described herein, the device 1005 (e.g., aprocessor controlling or otherwise coupled to the receiver 1010, thetransmitter 1015, the communications manager 1020, or a combinationthereof) may support techniques for configuring UEs for transmission ofmultiple repetitions of an uplink communication to multiple differentTRPs, such that the different repetitions may use transmissionparameters that are suitable for the particular TRP associated with therepetition. Such techniques may allow for enhanced reliability ofwireless communications, and thus provide more efficient utilization ofcommunication resources, reduced power consumption (through reducedretransmissions), reduced latency (through reduced retransmission), andmore efficient utilization of communication resources. Further, suchtechniques provide for flexibility in scheduling uplink communicationswith repetitions based on one or multiple SRS resource sets, which canenhance network efficiency through efficient scheduling of uplinkcommunications in accordance with available network and wirelessresources, and using reduced DCI overhead.

FIG. 11 shows a block diagram 1100 of a device 1105 that supports rankand resource set signaling techniques for multiple TRP communications inaccordance with aspects of the present disclosure. The device 1105 maybe an example of aspects of a device 1005 or a base station 105 asdescribed herein. The device 1105 may include a receiver 1110, atransmitter 1115, and a communications manager 1120. The device 1105 mayalso include a processor. Each of these components may be incommunication with one another (e.g., via one or more buses).

The receiver 1110 may provide a means for receiving information such aspackets, user data, control information, or any combination thereofassociated with various information channels (e.g., control channels,data channels, information channels related to rank and resource setsignaling techniques for multiple TRP communications). Information maybe passed on to other components of the device 1105. The receiver 1110may utilize a single antenna or a set of multiple antennas.

The transmitter 1115 may provide a means for transmitting signalsgenerated by other components of the device 1105. For example, thetransmitter 1115 may transmit information such as packets, user data,control information, or any combination thereof associated with variousinformation channels (e.g., control channels, data channels, informationchannels related to rank and resource set signaling techniques formultiple TRP communications). In some examples, the transmitter 1115 maybe co-located with a receiver 1110 in a transceiver module. Thetransmitter 1115 may utilize a single antenna or a set of multipleantennas.

The device 1105, or various components thereof, may be an example ofmeans for performing various aspects of rank and resource set signalingtechniques for multiple TRP communications as described herein. Forexample, the communications manager 1120 may include an SRSconfiguration manager 1125, an SRS resource set manager 1130, a controlinformation manager 1135, an uplink communication manager 1140, or anycombination thereof. The communications manager 1120 may be an exampleof aspects of a communications manager 1020 as described herein. In someexamples, the communications manager 1120, or various componentsthereof, may be configured to perform various operations (e.g.,receiving, monitoring, transmitting) using or otherwise in cooperationwith the receiver 1110, the transmitter 1115, or both. For example, thecommunications manager 1120 may receive information from the receiver1110, send information to the transmitter 1115, or be integrated incombination with the receiver 1110, the transmitter 1115, or both toreceive information, transmit information, or perform various otheroperations as described herein.

The communications manager 1120 may support wireless communication atthe device 1105 (e.g., a base station 105) in accordance with examplesas disclosed herein. The SRS configuration manager 1125 may beconfigured as or otherwise support a means for transmitting, to a UE, acontrol information configuration that indicates a quantity of bits thatare to be included in a control information field that indicates one ortwo SRS resource sets with which a first uplink communication is to beassociated. The SRS resource set manager 1130 may be configured as orotherwise support a means for determining whether one SRS resource setor two SRS resource sets are associated with the first uplinkcommunication. The control information manager 1135 may be configured asor otherwise support a means for transmitting, to the UE, a firstcontrol information communication that includes the control informationfield and that schedules the first uplink communication for the UE andindicates whether one SRS resource set or two SRS resource sets areassociated with the first uplink communication. The uplink communicationmanager 1140 may be configured as or otherwise support a means forreceiving the first uplink communication from the UE based on the firstcontrol information communication.

FIG. 12 shows a block diagram 1200 of a communications manager 1220 thatsupports rank and resource set signaling techniques for multiple TRPcommunications in accordance with aspects of the present disclosure. Thecommunications manager 1220 may be an example of aspects of acommunications manager 1020, a communications manager 1120, or both, asdescribed herein. The communications manager 1220, or various componentsthereof, may be an example of means for performing various aspects ofrank and resource set signaling techniques for multiple TRPcommunications as described herein. For example, the communicationsmanager 1220 may include an SRS configuration manager 1225, an SRSresource set manager 1230, a control information manager 1235, an uplinkcommunication manager 1240, a mapping manager 1245, or any combinationthereof. Each of these components may communicate, directly orindirectly, with one another (e.g., via one or more buses).

The communications manager 1220 may support wireless communication atthe device 1205 (e.g., a base station 105) in accordance with examplesas disclosed herein. The SRS configuration manager 1225 may beconfigured as or otherwise support a means for transmitting, to a UE, acontrol information configuration that indicates a quantity of bits thatare to be included in a control information field that indicates one ortwo SRS resource sets with which a first uplink communication is to beassociated. The SRS resource set manager 1230 may be configured as orotherwise support a means for determining whether one SRS resource setor two SRS resource sets are associated with the first uplinkcommunication. The control information manager 1235 may be configured asor otherwise support a means for transmitting, to the UE, a firstcontrol information communication that includes the control informationfield and that schedules the first uplink communication for the UE andindicates whether one SRS resource set or two SRS resource sets areassociated with the first uplink communication. The uplink communicationmanager 1240 may be configured as or otherwise support a means forreceiving the first uplink communication from the UE based on the firstcontrol information communication.

In some examples, the control information field further indicates anumber of SRS resources to be associated with the first uplinkcommunication. In some examples, a first bit of the first controlinformation communication indicates whether one or two SRS resource setsare associated with the first uplink communication, and where thecontrol information field includes a set of bits that indicate a numberof SRS resources for each SRS resource set associated with the firstuplink communication. In some examples, the first bit is an initial bitof the control information field, or is in a separate field in the firstcontrol information communication. In some examples, the set of bitsincludes a maximum of a first number of bits or a second number of bits,the first number of bits determined based on a first maximum rank whenone SRS resource set is associated with the first uplink communication,and the second number of bits determined based on a second maximum rankset when two SRS resource sets are associated with the first uplinkcommunication. In some examples, the second maximum rank is less thanthe first maximum rank. In some examples, the second maximum rank is afixed value or a configured value that is provided with the controlinformation configuration. In some examples, the configured value of thesecond maximum rank is based on a capability of the UE that istransmitted to the device 1205. In some examples, zero-padding is usedin the set of bits when a number of bits necessary to indicate the rankof the one or two SRS resource sets is less than a total number of bitsof the set of bits.

In some examples, the first number of bits is determined based on thefirst SRS resource set having a different number of SRS resources thanthe second SRS resource set. In some examples, the first number of bitsis associated with the first SRS resource set.

In some examples, the first number of bits is associated with either thefirst SRS resource set or the second SRS resource set, and a separatebit in the control information field provides an indication of which ofthe first SRS resource set or the second SRS resource set is associatedwith the first uplink communication. In some examples, the second numberof bits is associated with both the first SRS resource set and thesecond SRS resource set, and a first subset of the second number of bitsindicates one or more SRS resources within the first SRS resource setand a second subset of the second number of bits indicates one or moreSRS resources within the second SRS resource set. In some examples, thesecond number of bits is associated with both the first SRS resource setand the second SRS resource set, and provides a joint indication of oneor more SRS resources within each of the SRS resource sets based on asame number of layers associated with each SRS resource set.

In some examples, the mapping manager 1245 may be configured as orotherwise support a means for determining a number of SRS resources foreach SRS resource set associated with the first uplink communication. Insome examples, the mapping manager 1245 may be configured as orotherwise support a means for identifying a mapping between a codepointand the determined number of SRS resources. In some examples, themapping manager 1245 may be configured as or otherwise support a meansfor where the control information field indicates the codepoint.

In some examples, different bit values of the control information fieldare mapped to different possibilities of the SRS resources that areassociated with the first uplink communication. In some examples, afirst SRS resource set is ordered ahead of a second SRS resource set,and the quantity of bits that are included in the control informationfield is determined as a sum of a first number of possibilities toindicate a first number of SRS resources associated with the first SRSresource set when a single SRS resource set is associated with the firstuplink communication, and a second number of possibilities to indicate asecond number of SRS resources associated with both the first and thesecond SRS resource set when both the first SRS resource set and thesecond SRS resource set are associated with the first uplinkcommunication. In some examples, a first SRS resource set or a secondSRS resource set is ordered as an initial SRS resource set. In someexamples, where the quantity of bits that are included in the controlinformation field is determined as a sum of a first number ofpossibilities to indicate a first number of SRS resources associatedwith the initial SRS resource set when a single SRS resource set isassociated with the first uplink communication, and a second number ofpossibilities to indicate a second number of SRS resources associatedwith both the first and the second SRS resource set when a both thefirst SRS resource set and the second SRS resource set are associatedwith the first uplink communication.

FIG. 13 shows a diagram of a system 1300 including a device 1305 thatsupports rank and resource set signaling techniques for multiple TRPcommunications in accordance with aspects of the present disclosure. Thedevice 1305 may be an example of or include the components of a device1005, a device 1105, or a base station 105 as described herein. Thedevice 1305 may communicate wirelessly with one or more base stations105, UEs 115, or any combination thereof. The device 1305 may includecomponents for bi-directional voice and data communications includingcomponents for transmitting and receiving communications, such as acommunications manager 1320, a network communications manager 1310, atransceiver 1315, an antenna 1325, a memory 1330, code 1335, a processor1340, and an inter-station communications manager 1345. These componentsmay be in electronic communication or otherwise coupled (e.g.,operatively, communicatively, functionally, electronically,electrically) via one or more buses (e.g., a bus 1350).

The network communications manager 1310 may manage communications with acore network 130 (e.g., via one or more wired backhaul links). Forexample, the network communications manager 1310 may manage the transferof data communications for client devices, such as one or more UEs 115.

In some cases, the device 1305 may include a single antenna 1325.However, in some other cases the device 1305 may have more than oneantenna 1325, which may be capable of concurrently transmitting orreceiving multiple wireless transmissions. The transceiver 1315 maycommunicate bi-directionally, via the one or more antennas 1325, wired,or wireless links as described herein. For example, the transceiver 1315may represent a wireless transceiver and may communicatebi-directionally with another wireless transceiver. The transceiver 1315may also include a modem to modulate the packets, to provide themodulated packets to one or more antennas 1325 for transmission, and todemodulate packets received from the one or more antennas 1325. Thetransceiver 1315, or the transceiver 1315 and one or more antennas 1325,may be an example of a transmitter 1015, a transmitter 1115, a receiver1010, a receiver 1110, or any combination thereof or component thereof,as described herein.

The memory 1330 may include RAM and ROM. The memory 1330 may storecomputer-readable, computer-executable code 1335 including instructionsthat, when executed by the processor 1340, cause the device 1305 toperform various functions described herein. The code 1335 may be storedin a non-transitory computer-readable medium such as system memory oranother type of memory. In some cases, the code 1335 may not be directlyexecutable by the processor 1340 but may cause a computer (e.g., whencompiled and executed) to perform functions described herein. In somecases, the memory 1330 may contain, among other things, a BIOS which maycontrol basic hardware or software operation such as the interactionwith peripheral components or devices.

The processor 1340 may include an intelligent hardware device (e.g., ageneral-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, anFPGA, a programmable logic device, a discrete gate or transistor logiccomponent, a discrete hardware component, or any combination thereof).In some cases, the processor 1340 may be configured to operate a memoryarray using a memory controller. In some other cases, a memorycontroller may be integrated into the processor 1340. The processor 1340may be configured to execute computer-readable instructions stored in amemory (e.g., the memory 1330) to cause the device 1305 to performvarious functions (e.g., functions or tasks supporting rank and resourceset signaling techniques for multiple TRP communications). For example,the device 1305 or a component of the device 1305 may include aprocessor 1340 and memory 1330 coupled to the processor 1340, theprocessor 1340 and memory 1330 configured to perform various functionsdescribed herein.

The inter-station communications manager 1345 may manage communicationswith other base stations 105, and may include a controller or schedulerfor controlling communications with UEs 115 in cooperation with otherbase stations 105. For example, the inter-station communications manager1345 may coordinate scheduling for transmissions to UEs 115 for variousinterference mitigation techniques such as beamforming or jointtransmission. In some examples, the inter-station communications manager1345 may provide an X2 interface within an LTE/LTE-A wirelesscommunications network technology to provide communication between basestations 105.

The communications manager 1320 may support wireless communication atthe device 1305 (e.g., a base station 105) in accordance with examplesas disclosed herein. For example, the communications manager 1320 may beconfigured as or otherwise support a means for transmitting, to a UE, acontrol information configuration that indicates a quantity of bits thatare to be included in a control information field that indicates one ortwo SRS resource sets with which a first uplink communication is to beassociated. The communications manager 1320 may be configured as orotherwise support a means for determining whether one SRS resource setor two SRS resource sets are associated with the first uplinkcommunication. The communications manager 1320 may be configured as orotherwise support a means for transmitting, to the UE, a first controlinformation communication that includes the control information fieldand that schedules the first uplink communication for the UE andindicates whether one SRS resource set or two SRS resource sets areassociated with the first uplink communication. The communicationsmanager 1320 may be configured as or otherwise support a means forreceiving the first uplink communication from the UE based on the firstcontrol information communication.

By including or configuring the communications manager 1320 inaccordance with examples as described herein, the device 1305 maysupport techniques for configuring UEs for transmission of multiplerepetitions of an uplink communication to multiple different TRPs, suchthat the different repetitions may use transmission parameters that aresuitable for the particular TRP associated with the repetition. Suchtechniques may allow for enhanced reliability of wirelesscommunications, and thus provide more efficient utilization ofcommunication resources, reduced power consumption (through reducedretransmissions), reduced latency (through reduced retransmission), andmore efficient utilization of communication resources. Further, suchtechniques provide for flexibility in scheduling uplink communicationswith repetitions based on one or multiple SRS resource sets, which canenhance network efficiency through efficient scheduling of uplinkcommunications in accordance with available network and wirelessresources, and using reduced DCI overhead.

In some examples, the communications manager 1320 may be configured toperform various operations (e.g., receiving, monitoring, transmitting)using or otherwise in cooperation with the transceiver 1315, the one ormore antennas 1325, or any combination thereof. Although thecommunications manager 1320 is illustrated as a separate component, insome examples, one or more functions described with reference to thecommunications manager 1320 may be supported by or performed by theprocessor 1340, the memory 1330, the code 1335, or any combinationthereof. For example, the code 1335 may include instructions executableby the processor 1340 to cause the device 1305 to perform variousaspects of rank and resource set signaling techniques for multiple TRPcommunications as described herein, or the processor 1340 and the memory1330 may be otherwise configured to perform or support such operations.

FIG. 14 shows a flowchart illustrating a method 1400 that supports rankand resource set signaling techniques for multiple TRP communications inaccordance with aspects of the present disclosure. The operations of themethod 1400 may be implemented by a UE or its components as describedherein. For example, the operations of the method 1400 may be performedby a UE 115 as described with reference to FIGS. 1 through 9. In someexamples, a UE may execute a set of instructions to control thefunctional elements of the UE to perform the described functions.Additionally or alternatively, the UE may perform aspects of thedescribed functions using special-purpose hardware.

At 1405, the method may include receiving, from a base station, acontrol information configuration that indicates a quantity of bits thatare to be included in a control information field that indicates one ortwo SRS resource sets with which a first uplink communication is to beassociated. The operations of 1405 may be performed in accordance withexamples as disclosed herein. In some examples, aspects of theoperations of 1405 may be performed by an SRS configuration manager 825as described with reference to FIG. 8.

At 1410, the method may include receiving, from the base station, afirst control information communication that includes the controlinformation field and that schedules the first uplink communication forthe UE. The operations of 1410 may be performed in accordance withexamples as disclosed herein. In some examples, aspects of theoperations of 1410 may be performed by a control information manager 830as described with reference to FIG. 8.

At 1415, the method may include determining, based on the first controlinformation communication and the control information configuration,whether one or two SRS resource sets are associated with the firstuplink communication. The operations of 1415 may be performed inaccordance with examples as disclosed herein. In some examples, aspectsof the operations of 1415 may be performed by an SRS resource setmanager 835 as described with reference to FIG. 8.

At 1420, the method may include transmitting the first uplinkcommunication to the base station based on the determining. Theoperations of 1420 may be performed in accordance with examples asdisclosed herein. In some examples, aspects of the operations of 1420may be performed by an uplink communication manager 840 as describedwith reference to FIG. 8.

FIG. 15 shows a flowchart illustrating a method 1500 that supports rankand resource set signaling techniques for multiple TRP communications inaccordance with aspects of the present disclosure. The operations of themethod 1500 may be implemented by a UE or its components as describedherein. For example, the operations of the method 1500 may be performedby a UE 115 as described with reference to FIGS. 1 through 9. In someexamples, a UE may execute a set of instructions to control thefunctional elements of the UE to perform the described functions.Additionally or alternatively, the UE may perform aspects of thedescribed functions using special-purpose hardware.

At 1505, the method may include receiving, from a base station, acontrol information configuration that indicates a quantity of bits thatare to be included in a control information field that indicates one ortwo SRS resource sets with which a first uplink communication is to beassociated. The operations of 1505 may be performed in accordance withexamples as disclosed herein. In some examples, aspects of theoperations of 1505 may be performed by an SRS configuration manager 825as described with reference to FIG. 8.

At 1510, the method may include receiving, from the base station, afirst control information communication that includes the controlinformation field and that schedules the first uplink communication forthe UE. The operations of 1510 may be performed in accordance withexamples as disclosed herein. In some examples, aspects of theoperations of 1510 may be performed by a control information manager 830as described with reference to FIG. 8.

At 1515, the method may include determining, based on the first controlinformation communication and the control information configuration,whether one or two SRS resource sets are associated with the firstuplink communication. The operations of 1515 may be performed inaccordance with examples as disclosed herein. In some examples, aspectsof the operations of 1515 may be performed by an SRS resource setmanager 835 as described with reference to FIG. 8.

At 1520, the method may include determining, based on the first controlinformation communication and the control information configuration, thenumber of SRS resources for each SRS resource set associated with thefirst uplink communication. The operations of 1520 may be performed inaccordance with examples as disclosed herein. In some examples, aspectsof the operations of 1520 may be performed by an SRS resource setmanager 835 as described with reference to FIG. 8.

At 1525, the method may include transmitting the first uplinkcommunication to the base station based on the determining. Theoperations of 1525 may be performed in accordance with examples asdisclosed herein. In some examples, aspects of the operations of 1525may be performed by an uplink communication manager 840 as describedwith reference to FIG. 8.

FIG. 16 shows a flowchart illustrating a method 1600 that supports rankand resource set signaling techniques for multiple TRP communications inaccordance with aspects of the present disclosure. The operations of themethod 1600 may be implemented by a UE or its components as describedherein. For example, the operations of the method 1600 may be performedby a UE 115 as described with reference to FIGS. 1 through 9. In someexamples, a UE may execute a set of instructions to control thefunctional elements of the UE to perform the described functions.Additionally or alternatively, the UE may perform aspects of thedescribed functions using special-purpose hardware.

At 1605, the method may include receiving, from a base station, acontrol information configuration that indicates a quantity of bits thatare to be included in a control information field that indicates one ortwo SRS resource sets with which a first uplink communication is to beassociated. The operations of 1605 may be performed in accordance withexamples as disclosed herein. In some examples, aspects of theoperations of 1605 may be performed by an SRS configuration manager 825as described with reference to FIG. 8.

At 1610, the method may include receiving, from the base station, afirst control information communication that includes the controlinformation field and that schedules the first uplink communication forthe UE. The operations of 1610 may be performed in accordance withexamples as disclosed herein. In some examples, aspects of theoperations of 1610 may be performed by a control information manager 830as described with reference to FIG. 8.

At 1615, the method may include determining, based on a first bit of thefirst control information communication, whether one or two SRS resourcesets are associated with the first uplink communication, and where thecontrol information field includes a set of bits that indicate a numberof SRS resources for each SRS resource set associated with the firstuplink communication. The operations of 1615 may be performed inaccordance with examples as disclosed herein. In some examples, aspectsof the operations of 1615 may be performed by a control informationmanager 830 as described with reference to FIG. 8.

At 1620, the method may include transmitting the first uplinkcommunication to the base station based on the determining. Theoperations of 1620 may be performed in accordance with examples asdisclosed herein. In some examples, aspects of the operations of 1620may be performed by an uplink communication manager 840 as describedwith reference to FIG. 8.

FIG. 17 shows a flowchart illustrating a method 1700 that supports rankand resource set signaling techniques for multiple TRP communications inaccordance with aspects of the present disclosure. The operations of themethod 1700 may be implemented by a UE or its components as describedherein. For example, the operations of the method 1700 may be performedby a UE 115 as described with reference to FIGS. 1 through 9. In someexamples, a UE may execute a set of instructions to control thefunctional elements of the UE to perform the described functions.Additionally or alternatively, the UE may perform aspects of thedescribed functions using special-purpose hardware.

At 1705, the method may include receiving, from a base station, acontrol information configuration that indicates a quantity of bits thatare to be included in a control information field that indicates one ortwo SRS resource sets with which a first uplink communication is to beassociated. The operations of 1705 may be performed in accordance withexamples as disclosed herein. In some examples, aspects of theoperations of 1705 may be performed by an SRS configuration manager 825as described with reference to FIG. 8.

At 1710, the method may include receiving, from the base station, afirst control information communication that includes the controlinformation field and that schedules the first uplink communication forthe UE. The operations of 1710 may be performed in accordance withexamples as disclosed herein. In some examples, aspects of theoperations of 1710 may be performed by a control information manager 830as described with reference to FIG. 8.

At 1715, the method may include decoding the control information fieldto identify a set of bits. The operations of 1715 may be performed inaccordance with examples as disclosed herein. In some examples, aspectsof the operations of 1715 may be performed by a mapping manager 845 asdescribed with reference to FIG. 8.

At 1720, the method may include identifying, based on a mapping for theset of bits, a number of SRS resources for each SRS resource setassociated with the first uplink communication. The operations of 1720may be performed in accordance with examples as disclosed herein. Insome examples, aspects of the operations of 1720 may be performed by amapping manager 845 as described with reference to FIG. 8.

At 1725, the method may include transmitting the first uplinkcommunication to the base station based on the mapping. The operationsof 1725 may be performed in accordance with examples as disclosedherein. In some examples, aspects of the operations of 1725 may beperformed by an uplink communication manager 840 as described withreference to FIG. 8.

FIG. 18 shows a flowchart illustrating a method 1800 that supports rankand resource set signaling techniques for multiple TRP communications inaccordance with aspects of the present disclosure. The operations of themethod 1800 may be implemented by a base station or its components asdescribed herein. For example, the operations of the method 1800 may beperformed by a base station 105 as described with reference to FIGS. 1through 5 and 10 through 13. In some examples, a base station mayexecute a set of instructions to control the functional elements of thebase station to perform the described functions. Additionally oralternatively, the base station may perform aspects of the describedfunctions using special-purpose hardware.

At 1805, the method may include transmitting, to a UE, a controlinformation configuration that indicates a quantity of bits that are tobe included in a control information field that indicates one or two SRSresource sets with which a first uplink communication is to beassociated. The operations of 1805 may be performed in accordance withexamples as disclosed herein. In some examples, aspects of theoperations of 1805 may be performed by an SRS configuration manager 1225as described with reference to FIG. 12.

At 1810, the method may include determining whether one SRS resource setor two SRS resource sets are associated with the first uplinkcommunication. The operations of 1810 may be performed in accordancewith examples as disclosed herein. In some examples, aspects of theoperations of 1810 may be performed by an SRS resource set manager 1230as described with reference to FIG. 12.

At 1815, the method may include transmitting, to the UE, a first controlinformation communication that includes the control information fieldand that schedules the first uplink communication for the UE andindicates whether one SRS resource set or two SRS resource sets areassociated with the first uplink communication. The operations of 1815may be performed in accordance with examples as disclosed herein. Insome examples, aspects of the operations of 1815 may be performed by acontrol information manager 1235 as described with reference to FIG. 12.

At 1820, the method may include receiving the first uplink communicationfrom the UE based on the first control information communication. Theoperations of 1820 may be performed in accordance with examples asdisclosed herein. In some examples, aspects of the operations of 1820may be performed by an uplink communication manager 1240 as describedwith reference to FIG. 12.

FIG. 19 shows a flowchart illustrating a method 1900 that supports rankand resource set signaling techniques for multiple TRP communications inaccordance with aspects of the present disclosure. The operations of themethod 1900 may be implemented by a base station or its components asdescribed herein. For example, the operations of the method 1900 may beperformed by a base station 105 as described with reference to FIGS. 1through 5 and 10 through 13. In some examples, a base station mayexecute a set of instructions to control the functional elements of thebase station to perform the described functions. Additionally oralternatively, the base station may perform aspects of the describedfunctions using special-purpose hardware.

At 1905, the method may include transmitting, to a UE, a controlinformation configuration that indicates a quantity of bits that are tobe included in a control information field that indicates one or two SRSresource sets with which a first uplink communication is to beassociated. The operations of 1905 may be performed in accordance withexamples as disclosed herein. In some examples, aspects of theoperations of 1905 may be performed by an SRS configuration manager 1225as described with reference to FIG. 12.

At 1910, the method may include determining whether one SRS resource setor two SRS resource sets are associated with the first uplinkcommunication. The operations of 1910 may be performed in accordancewith examples as disclosed herein. In some examples, aspects of theoperations of 1910 may be performed by an SRS resource set manager 1230as described with reference to FIG. 12.

At 1915, the method may include determining a number of SRS resourcesfor each SRS resource set associated with the first uplinkcommunication. The operations of 1915 may be performed in accordancewith examples as disclosed herein. In some examples, aspects of theoperations of 1915 may be performed by a mapping manager 1245 asdescribed with reference to FIG. 12.

At 1920, the method may include identifying a mapping between acodepoint and the determined number of SRS resources. The operations of1920 may be performed in accordance with examples as disclosed herein.In some examples, aspects of the operations of 1920 may be performed bya mapping manager 1245 as described with reference to FIG. 12.

At 1925, the method may include transmitting, to the UE, a first controlinformation communication that that indicates the codepoint. Theoperations of 1925 may be performed in accordance with examples asdisclosed herein. In some examples, aspects of the operations of 1925may be performed by a control information manager 1235 as described withreference to FIG. 12.

At 1930, the method may include receiving the first uplink communicationfrom the UE based on the first control information communication. Theoperations of 1930 may be performed in accordance with examples asdisclosed herein. In some examples, aspects of the operations of 1930may be performed by an uplink communication manager 1240 as describedwith reference to FIG. 12.

The following provides an overview of aspects of the present disclosure:

Aspect 1: A method for wireless communication at a UE, comprising:receiving, from a base station, a control information configuration thatindicates a quantity of bits that are to be included in a controlinformation field that indicates one or two sounding reference signalresource sets with which a first uplink communication is to beassociated; receiving, from the base station, a first controlinformation communication that includes the control information fieldand that schedules the first uplink communication for the UE;determining, based at least in part on the first control informationcommunication and the control information configuration, whether one ortwo sounding reference signal resource sets are associated with thefirst uplink communication; and transmitting the first uplinkcommunication to the base station based at least in part on thedetermining.

Aspect 2: The method of aspect 1, wherein the control information fieldfurther indicates a number of sounding reference signal resources to beassociated with the first uplink communication, and wherein thedetermining further comprises: determining, based at least in part onthe first control information communication and the control informationconfiguration, the number of sounding reference signal resources foreach sounding reference signal resource set associated with the firstuplink communication.

Aspect 3: The method of any of aspects 1 through 2, wherein thedetermining further comprises: determining, based at least in part on afirst bit of the first control information communication, whether one ortwo sounding reference signal resource sets are associated with thefirst uplink communication, and wherein the control information fieldincludes a set of bits that indicate a number of sounding referencesignal resources for each sounding reference signal resource setassociated with the first uplink communication.

Aspect 4: The method of aspect 3, wherein the first bit is an initialbit of the control information field, or is in a separate field in thefirst control information communication.

Aspect 5: The method of any of aspects 3 through 4, wherein the set ofbits includes a maximum of a first number of bits or a second number ofbits, the first number of bits determined based at least in part on afirst maximum rank when one sounding reference signal resource set isassociated with the first uplink communication, and the second number ofbits determined based at least in part on a second maximum rank when twosounding reference signal resource sets are associated with the firstuplink communication.

Aspect 6: The method of aspect 5, wherein the second maximum rank isless than the first maximum rank.

Aspect 7: The method of any of aspects 5 through 6, wherein the secondmaximum rank is a fixed value or a configured value that is providedwith the control information configuration.

Aspect 8: The method of aspect 7, wherein the configured value of thesecond maximum rank is based at least in part on a capability of the UEthat is transmitted to the base station.

Aspect 9: The method of any of aspects 5 through 8, wherein zero-paddingis used in the set of bits when a number of bits necessary to indicatethe rank of the one or two sounding reference signal resource sets isless than a total number of bits of the set of bits.

Aspect 10: The method of any of aspects 5 through 9, wherein the firstnumber of bits is determined based at least in part on the firstsounding reference signal resource set having a different number ofsounding reference signal resources than the second sounding referencesignal resource set.

Aspect 11: The method of aspect 10, wherein the first number of bits isassociated with the first sounding reference signal resource set.

Aspect 12: The method of aspect 5, wherein the first number of bits isassociated with either the first sounding reference signal resource setor the second sounding reference signal resource set, and a separate bitin the control information field provides an indication of which of thefirst sounding reference signal resource set or the second soundingreference signal resource set is associated with the first uplinkcommunication.

Aspect 13: The method of aspect 5, wherein the second number of bits isassociated with both the first sounding reference signal resource setand the second sounding reference signal resource set, and a firstsubset of the second number of bits indicates one or more soundingreference signal resources within the first sounding reference signalresource set and a second subset of the second number of bits indicatesone or more sounding reference signal resources within the secondsounding reference signal resource set.

Aspect 14: The method of aspect 5, wherein the second number of bits isassociated with both the first sounding reference signal resource setand the second sounding reference signal resource set, and provides ajoint indication of one or more sounding reference signal resourceswithin each sounding reference signal resource set based on a samenumber of layers associated with each sounding reference signal resourceset.

Aspect 15: The method of aspect 1, wherein the determining furthercomprises: decoding the control information field to identify a set ofbits; and identifying, based at least in part on a mapping for the setof bits, a number of sounding reference signal resources for eachsounding reference signal resource set associated with the first uplinkcommunication.

Aspect 16: The method of aspect 15, wherein a first sounding referencesignal resource set is ordered ahead of a second sounding referencesignal resource set, and the quantity of bits that are included in thecontrol information field is determined as a sum of a first number ofpossibilities to indicate a first number of sounding reference signalresources associated with the first sounding reference signal resourceset when a single sounding reference signal resource set is associatedwith the first uplink communication, and a second number ofpossibilities to indicate a second number of sounding reference signalresources associated with both the first and the second soundingreference signal resource set when both the first sounding referencesignal resource set and the second sounding reference signal resourceset are associated with the first uplink communication.

Aspect 17: The method of aspect 15, wherein: a first sounding referencesignal resource set or a second sounding reference signal resource setis ordered as an initial sounding reference signal resource set; and thequantity of bits that are included in the control information field isdetermined as a sum of a first number of possibilities to indicate afirst number of sounding reference signal resources associated with theinitial sounding reference signal resource set when a single soundingreference signal resource set is associated with the first uplinkcommunication, and a second number of possibilities to indicate a secondnumber of sounding reference signal resources associated with both thefirst and the second sounding reference signal resource set when a boththe first sounding reference signal resource set and the second soundingreference signal resource set are associated with the first uplinkcommunication.

Aspect 18: The method of any of aspects 15 through 17, wherein differentbit values of the control information field are mapped to differentpossibilities of a number of the sounding reference signal resourcesthat are associated with the first uplink communication.

Aspect 19: A method for wireless communication at a base station,comprising: transmitting, to a UE, a control information configurationthat indicates a quantity of bits that are to be included in a controlinformation field that indicates one or two sounding reference signalresource sets with which a first uplink communication is to beassociated; determining whether one sounding reference signal resourceset or two sounding reference signal resource sets are associated withthe first uplink communication; transmitting, to the UE, a first controlinformation communication that includes the control information fieldand that schedules the first uplink communication for the UE andindicates whether one sounding reference signal resource set or twosounding reference signal resource sets are associated with the firstuplink communication; and receiving the first uplink communication fromthe UE based at least in part on the first control informationcommunication.

Aspect 20: The method of aspect 19, wherein the control informationfield further indicates a number of sounding reference signal resourcesto be associated with the first uplink communication.

Aspect 21: The method of any of aspects 19 through 20, wherein a firstbit of the first control information communication indicates whether oneor two sounding reference signal resource sets are associated with thefirst uplink communication, and wherein the control information fieldincludes a set of bits that indicate a number of sounding referencesignal resources for each sounding reference signal resource setassociated with the first uplink communication.

Aspect 22: The method of aspect 21, wherein the first bit is an initialbit of the control information field, or is in a separate field in thefirst control information communication.

Aspect 23: The method of any of aspects 21 through 22, wherein the setof bits includes a maximum of a first number of bits or a second numberof bits, the first number of bits determined based at least in part on afirst maximum rank when one sounding reference signal resource set isassociated with the first uplink communication, and the second number ofbits determined based at least in part on a second maximum rank set whentwo sounding reference signal resource sets are associated with thefirst uplink communication.

Aspect 24: The method of aspect 23, wherein the second maximum rank isless than the first maximum rank.

Aspect 25: The method of any of aspects 23 through 24, wherein thesecond maximum rank is a fixed value or a configured value that isprovided with the control information configuration.

Aspect 26: The method of aspect 25, wherein the configured value of thesecond maximum rank is based at least in part on a capability of the UEthat is transmitted to the base station.

Aspect 27: The method of any of aspects 23 through 26, whereinzero-padding is used in the set of bits when a number of bits necessaryto indicate the rank of the one or two sounding reference signalresource sets is less than a total number of bits of the set of bits.

Aspect 28: The method of any of aspects 23 through 27, wherein the firstnumber of bits is determined based at least in part on the firstsounding reference signal resource set having a different number ofsounding reference signal resources than the second sounding referencesignal resource set.

Aspect 29: The method of aspect 28, wherein the first number of bits isassociated with the first sounding reference signal resource set.

Aspect 30: The method of aspects 23, wherein the first number of bits isassociated with either the first sounding reference signal resource setor the second sounding reference signal resource set, and a separate bitin the control information field provides an indication of which of thefirst sounding reference signal resource set or the second soundingreference signal resource set is associated with the first uplinkcommunication.

Aspect 31: The method of aspect 23, wherein the second number of bits isassociated with both the first sounding reference signal resource setand the second sounding reference signal resource set, and a firstsubset of the second number of bits indicates one or more soundingreference signal resources within the first sounding reference signalresource set and a second subset of the second number of bits indicatesone or more sounding reference signal resources within the secondsounding reference signal resource set.

Aspect 32: The method of aspect 23, wherein the second number of bits isassociated with both the first sounding reference signal resource setand the second sounding reference signal resource set, and provides ajoint indication of one or more sounding reference signal resourceswithin each sounding reference signal resource set based on a samenumber of layers associated with each sounding reference signal resourceset.

Aspect 33: The method of aspect 19, further comprising: determining anumber of sounding reference signal resources for each soundingreference signal resource set associated with the first uplinkcommunication; identifying a mapping between a codepoint and thedetermined number of sounding reference signal resources, and whereinthe control information field indicates the codepoint.

Aspect 34: The method of aspect 33, wherein different bit values of thecontrol information field are mapped to different possibilities of thesounding reference signal resources that are associated with the firstuplink communication.

Aspect 35: The method of aspect 19, wherein a first sounding referencesignal resource set is ordered ahead of a second sounding referencesignal resource set, and the quantity of bits that are included in thecontrol information field is determined as a sum of a first number ofpossibilities to indicate a first number of sounding reference signalresources associated with the first sounding reference signal resourceset when a single sounding reference signal resource set is associatedwith the first uplink communication, and a second number ofpossibilities to indicate a second number of sounding reference signalresources associated with both the first and the second soundingreference signal resource set when both the first sounding referencesignal resource set and the second sounding reference signal resourceset are associated with the first uplink communication.

Aspect 36: The method of aspect 19, wherein: a first sounding referencesignal resource set or a second sounding reference signal resource setis ordered as an initial sounding reference signal resource set; and thequantity of bits that are included in the control information field isdetermined as a sum of a first number of possibilities to indicate afirst number of sounding reference signal resources associated with theinitial sounding reference signal resource set when a single soundingreference signal resource set is associated with the first uplinkcommunication, and a second number of possibilities to indicate a secondnumber of sounding reference signal resources associated with both thefirst and the second sounding reference signal resource set when a boththe first sounding reference signal resource set and the second soundingreference signal resource set are associated with the first uplinkcommunication.

Aspect 37: An apparatus for wireless communication at a UE, comprising aprocessor; memory coupled with the processor; and instructions stored inthe memory and executable by the processor to cause the apparatus toperform a method of any of aspects 1 through 18.

Aspect 38: An apparatus for wireless communication at a UE, comprisingat least one means for performing a method of any of aspects 1 through18.

Aspect 39: A non-transitory computer-readable medium storing code forwireless communication at a UE, the code comprising instructionsexecutable by a processor to perform a method of any of aspects 1through 18.

Aspect 40: An apparatus for wireless communication at a base station,comprising a processor; memory coupled with the processor; andinstructions stored in the memory and executable by the processor tocause the apparatus to perform a method of any of aspects 19 through 36.

Aspect 41: An apparatus for wireless communication at a base station,comprising at least one means for performing a method of any of aspects19 through 36.

Aspect 42: A non-transitory computer-readable medium storing code forwireless communication at a base station, the code comprisinginstructions executable by a processor to perform a method of any ofaspects 19 through 36.

It should be noted that the methods described herein describe possibleimplementations, and that the operations and the steps may be rearrangedor otherwise modified and that other implementations are possible.Further, aspects from two or more of the methods may be combined.

Although aspects of an LTE, LTE-A, LTE-A Pro, or NR system may bedescribed for purposes of example, and LTE, LTE-A, LTE-A Pro, or NRterminology may be used in much of the description, the techniquesdescribed herein are applicable beyond LTE, LTE-A, LTE-A Pro, or NRnetworks. For example, the described techniques may be applicable tovarious other wireless communications systems such as Ultra MobileBroadband (UMB), Institute of Electrical and Electronics Engineers(IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, aswell as other systems and radio technologies not explicitly mentionedherein.

Information and signals described herein may be represented using any ofa variety of different technologies and techniques. For example, data,instructions, commands, information, signals, bits, symbols, and chipsthat may be referenced throughout the description may be represented byvoltages, currents, electromagnetic waves, magnetic fields or particles,optical fields or particles, or any combination thereof.

The various illustrative blocks and components described in connectionwith the disclosure herein may be implemented or performed with ageneral-purpose processor, a DSP, an ASIC, a CPU, an FPGA or otherprogrammable logic device, discrete gate or transistor logic, discretehardware components, or any combination thereof designed to perform thefunctions described herein. A general-purpose processor may be amicroprocessor, but in the alternative, the processor may be anyprocessor, controller, microcontroller, or state machine. A processormay also be implemented as a combination of computing devices (e.g., acombination of a DSP and a microprocessor, multiple microprocessors, oneor more microprocessors in conjunction with a DSP core, or any othersuch configuration).

The functions described herein may be implemented in hardware, softwareexecuted by a processor, firmware, or any combination thereof. Ifimplemented in software executed by a processor, the functions may bestored on or transmitted over as one or more instructions or code on acomputer-readable medium. Other examples and implementations are withinthe scope of the disclosure and appended claims. For example, due to thenature of software, functions described herein may be implemented usingsoftware executed by a processor, hardware, firmware, hardwiring, orcombinations of any of these. Features implementing functions may alsobe physically located at various positions, including being distributedsuch that portions of functions are implemented at different physicallocations.

Computer-readable media includes both non-transitory computer storagemedia and communication media including any medium that facilitatestransfer of a computer program from one place to another. Anon-transitory storage medium may be any available medium that may beaccessed by a general-purpose or special-purpose computer. By way ofexample, and not limitation, non-transitory computer-readable media mayinclude RAM, ROM, electrically erasable programmable ROM (EEPROM), flashmemory, compact disk (CD) ROM or other optical disk storage, magneticdisk storage or other magnetic storage devices, or any othernon-transitory medium that may be used to carry or store desired programcode means in the form of instructions or data structures and that maybe accessed by a general-purpose or special-purpose computer, or ageneral-purpose or special-purpose processor. Also, any connection isproperly termed a computer-readable medium. For example, if the softwareis transmitted from a website, server, or other remote source using acoaxial cable, fiber optic cable, twisted pair, digital subscriber line(DSL), or wireless technologies such as infrared, radio, and microwave,then the coaxial cable, fiber optic cable, twisted pair, DSL, orwireless technologies such as infrared, radio, and microwave areincluded in the definition of computer-readable medium. Disk and disc,as used herein, include CD, laser disc, optical disc, digital versatiledisc (DVD), floppy disk and Blu-ray disc where disks usually reproducedata magnetically, while discs reproduce data optically with lasers.Combinations of the above are also included within the scope ofcomputer-readable media.

As used herein, including in the claims, “or” as used in a list of items(e.g., a list of items prefaced by a phrase such as “at least one of” or“one or more of”) indicates an inclusive list such that, for example, alist of at least one of A, B, or C means A or B or C or AB or AC or BCor ABC (i.e., A and B and C). Also, as used herein, the phrase “basedon” shall not be construed as a reference to a closed set of conditions.For example, an example step that is described as “based on condition A”may be based on both a condition A and a condition B without departingfrom the scope of the present disclosure. In other words, as usedherein, the phrase “based on” shall be construed in the same manner asthe phrase “based at least in part on.”

In the appended figures, similar components or features may have thesame reference label. Further, various components of the same type maybe distinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If just the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label, or othersubsequent reference label.

The description set forth herein, in connection with the appendeddrawings, describes example configurations and does not represent allthe examples that may be implemented or that are within the scope of theclaims. The term “example” used herein means “serving as an example,instance, or illustration,” and not “preferred” or “advantageous overother examples.” The detailed description includes specific details forthe purpose of providing an understanding of the described techniques.These techniques, however, may be practiced without these specificdetails. In some instances, known structures and devices are shown inblock diagram form in order to avoid obscuring the concepts of thedescribed examples.

The description herein is provided to enable a person having ordinaryskill in the art to make or use the disclosure. Various modifications tothe disclosure will be apparent to a person having ordinary skill in theart, and the generic principles defined herein may be applied to othervariations without departing from the scope of the disclosure. Thus, thedisclosure is not limited to the examples and designs described hereinbut is to be accorded the broadest scope consistent with the principlesand novel features disclosed herein.

What is claimed is:
 1. A method for wireless communication at a userequipment (UE), comprising: receiving, from a base station, a controlinformation configuration that indicates a quantity of bits that are tobe included in a control information field that indicates one or twosounding reference signal resource sets with which a first uplinkcommunication is to be associated; receiving, from the base station, afirst control information communication that includes the controlinformation field and that schedules the first uplink communication forthe UE; determining, based at least in part on the first controlinformation communication and the control information configuration,whether one or two sounding reference signal resource sets areassociated with the first uplink communication; and transmitting thefirst uplink communication to the base station based at least in part onthe determining.
 2. The method of claim 1, wherein the controlinformation field further indicates a number of sounding referencesignal resources to be associated with the first uplink communication,and wherein the determining further comprises: determining, based atleast in part on the first control information communication and thecontrol information configuration, the number of sounding referencesignal resources for each sounding reference signal resource setassociated with the first uplink communication.
 3. The method of claim1, wherein the determining further comprises: determining, based atleast in part on a first bit of the first control informationcommunication, whether one or two sounding reference signal resourcesets are associated with the first uplink communication, and wherein thecontrol information field includes a set of bits that indicate a numberof sounding reference signal resources for each sounding referencesignal resource set associated with the first uplink communication. 4.The method of claim 3, wherein the first bit is an initial bit of thecontrol information field, or is in a separate field in the firstcontrol information communication.
 5. The method of claim 3, wherein theset of bits includes a maximum of a first number of bits or a secondnumber of bits, the first number of bits determined based at least inpart on a first maximum rank when one sounding reference signal resourceset is associated with the first uplink communication, and the secondnumber of bits determined based at least in part on a second maximumrank when two sounding reference signal resource sets are associatedwith the first uplink communication.
 6. The method of claim 5, whereinthe second maximum rank is less than the first maximum rank.
 7. Themethod of claim 5, wherein the second maximum rank is a fixed value or aconfigured value that is provided with the control informationconfiguration.
 8. The method of claim 7, wherein the configured value ofthe second maximum rank is based at least in part on a capability of theUE that is transmitted to the base station.
 9. The method of claim 5,wherein zero-padding is used in the set of bits when a number of bitsnecessary to indicate a rank of the one or two sounding reference signalresource sets is less than a total number of bits of the set of bits.10. The method of claim 5, wherein the first number of bits isdetermined based at least in part on a first sounding reference signalresource set having a different number of sounding reference signalresources than a second sounding reference signal resource set.
 11. Themethod of claim 10, wherein the first number of bits is associated withthe first sounding reference signal resource set.
 12. The method ofclaim 10, wherein the first number of bits is associated with either thefirst sounding reference signal resource set or the second soundingreference signal resource set, and a separate bit in the controlinformation field provides an indication of which of the first soundingreference signal resource set or the second sounding reference signalresource set is associated with the first uplink communication.
 13. Themethod of claim 5, wherein the second number of bits is associated withboth a first sounding reference signal resource set and a secondsounding reference signal resource set, and a first subset of the secondnumber of bits indicates one or more sounding reference signal resourceswithin the first sounding reference signal resource set and a secondsubset of the second number of bits indicates one or more soundingreference signal resources within the second sounding reference signalresource set.
 14. The method of claim 5, wherein the second number ofbits is associated with both a first sounding reference signal resourceset and a second sounding reference signal resource set, and provides ajoint indication of one or more sounding reference signal resourceswithin each sounding reference signal resource set based on a samenumber of layers associated with each sounding reference signal resourceset.
 15. The method of claim 1, wherein the determining furthercomprises: decoding the control information field to identify a set ofbits; and identifying, based at least in part on a mapping for the setof bits, a number of sounding reference signal resources for eachsounding reference signal resource set associated with the first uplinkcommunication.
 16. The method of claim 15, wherein a first soundingreference signal resource set is ordered ahead of a second soundingreference signal resource set, and the quantity of bits that areincluded in the control information field is determined as a sum of afirst number of possibilities to indicate a first number of soundingreference signal resources associated with the first sounding referencesignal resource set when a single sounding reference signal resource setis associated with the first uplink communication, and a second numberof possibilities to indicate a second number of sounding referencesignal resources associated with both the first and the second soundingreference signal resource set when both the first sounding referencesignal resource set and the second sounding reference signal resourceset are associated with the first uplink communication.
 17. The methodof claim 15, wherein: a first sounding reference signal resource set ora second sounding reference signal resource set is ordered as an initialsounding reference signal resource set; and the quantity of bits thatare included in the control information field is determined as a sum ofa first number of possibilities to indicate a first number of soundingreference signal resources associated with the initial soundingreference signal resource set when a single sounding reference signalresource set is associated with the first uplink communication, and asecond number of possibilities to indicate a second number of soundingreference signal resources associated with both the first and the secondsounding reference signal resource set when a both the first soundingreference signal resource set and the second sounding reference signalresource set are associated with the first uplink communication.
 18. Themethod of claim 15, wherein different bit values of the controlinformation field are mapped to different possibilities of the number ofsounding reference signal resources that are associated with the firstuplink communication.
 19. A method for wireless communication at a basestation, comprising: transmitting, to a user equipment (UE), a controlinformation configuration that indicates a quantity of bits that are tobe included in a control information field that indicates one or twosounding reference signal resource sets with which a first uplinkcommunication is to be associated; determining whether one soundingreference signal resource set or two sounding reference signal resourcesets are associated with the first uplink communication; transmitting,to the UE, a first control information communication that includes thecontrol information field and that schedules the first uplinkcommunication for the UE and indicates whether one sounding referencesignal resource set or two sounding reference signal resource sets areassociated with the first uplink communication; and receiving the firstuplink communication from the UE based at least in part on the firstcontrol information communication.
 20. The method of claim 19, whereinthe control information field further indicates a number of soundingreference signal resources to be associated with the first uplinkcommunication.
 21. The method of claim 19, wherein a first bit of thefirst control information communication indicates whether one or twosounding reference signal resource sets are associated with the firstuplink communication, and wherein the control information field includesa set of bits that indicate a number of sounding reference signalresources for each sounding reference signal resource set associatedwith the first uplink communication.
 22. The method of claim 21, whereinthe first bit is an initial bit of the control information field, or isin a separate field in the first control information communication. 23.The method of claim 21, wherein the set of bits includes a maximum of afirst number of bits or a second number of bits, the first number ofbits determined based at least in part on a first maximum rank when onesounding reference signal resource set is associated with the firstuplink communication, and the second number of bits determined based atleast in part on a second maximum rank when two sounding referencesignal resource sets are associated with the first uplink communication.24. The method of claim 23, wherein the second maximum rank is less thanthe first maximum rank.
 25. The method of claim 23, wherein the secondmaximum rank is a fixed value or a configured value that is providedwith the control information configuration.
 26. The method of claim 25,wherein the configured value of the second maximum rank is based atleast in part on a capability of the UE that is transmitted to the basestation.
 27. The method of claim 23, wherein zero-padding is used in theset of bits when a number of bits necessary to indicate a rank of theone or two sounding reference signal resource sets is less than a totalnumber of bits of the set of bits.
 28. The method of claim 19, furthercomprising: determining a number of sounding reference signal resourcesfor each sounding reference signal resource set associated with thefirst uplink communication; identifying a mapping between a codepointand the determined number of sounding reference signal resources, andwherein the control information field indicates the codepoint.
 29. Anapparatus for wireless communication at a user equipment (UE),comprising: a processor; memory coupled with the processor; andinstructions stored in the memory and executable by the processor tocause the apparatus to: receive, from a base station, a controlinformation configuration that indicates a quantity of bits that are tobe included in a control information field that indicates one or twosounding reference signal resource sets with which a first uplinkcommunication is to be associated; receive, from the base station, afirst control information communication that includes the controlinformation field and that schedules the first uplink communication forthe UE; determine, based at least in part on the first controlinformation communication and the control information configuration,whether one or two sounding reference signal resource sets areassociated with the first uplink communication; and transmit the firstuplink communication to the base station based at least in part on thedetermining.
 30. An apparatus for wireless communication at a basestation, comprising: a processor; memory coupled with the processor; andinstructions stored in the memory and executable by the processor tocause the apparatus to: transmit, to a user equipment (UE), a controlinformation configuration that indicates a quantity of bits that are tobe included in a control information field that indicates one or twosounding reference signal resource sets with which a first uplinkcommunication is to be associated; determine whether one soundingreference signal resource set or two sounding reference signal resourcesets are associated with the first uplink communication; transmit, tothe UE, a first control information communication that includes thecontrol information field and that schedules the first uplinkcommunication for the UE and indicates whether one sounding referencesignal resource set or two sounding reference signal resource sets areassociated with the first uplink communication; and receive the firstuplink communication from the UE based at least in part on the firstcontrol information communication.